Relations between beam group beam failure recovery and cell level beam failure recovery

ABSTRACT

In operation, the UE in the cell (SpCell/SCell) may be configured to operate with beam group specific BFRs, cell-level BFRs, or combinations of them under a beam failure configuration that is determined according to various rules. A method of wireless communication performed by a user equipment (UE) and a UE is disclosed. The method includes determining a beam failure configuration for a serving cell, the beam failure configuration including at least one of a beam failure parameter of a beam group or a beam failure parameter of a cell; and detecting, in the serving cell based at least in part on the beam failure configuration, a beam failure recovery (BFR) based at least in part on the beam failure configuration. The beam failure configuration is determined based on various rules that control the operation of the BFR.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to and the benefit of the U.S.Provisional Patent Application No. 63/085,141, filed Sep. 29, 2020,titled “Relations between Beam Group Beam Failure Recovery and CellLevel Beam Failure Recovery,” which is hereby incorporated by referencein its entirety as if fully set forth below and for all applicablepurposes.

TECHNICAL FIELD

This application relates to wireless communication systems, and moreparticularly to relations between beam group beam failure recovery andcell level beam failure recovery.

INTRODUCTION

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). A wirelessmultiple-access communications system may include a number of basestations (BSs), each simultaneously supporting communications formultiple communication devices, which may be otherwise known as userequipment (UE).

To meet the growing demands for expanded mobile broadband connectivity,wireless communication technologies are advancing from the long-termevolution (LTE) technology to a next generation new radio (NR)technology, which may be referred to as 5^(th) Generation (5G). Forexample, NR is designed to provide a lower latency, a higher bandwidthor a higher throughput, and a higher reliability than LTE. NR isdesigned to operate over a wide array of spectrum bands, for example,from low-frequency bands below about 1 gigahertz (GHz) and mid-frequencybands from about 1 GHz to about 6 GHz, to high-frequency bands such asmmWave bands. NR is also designed to operate across different spectrumtypes, from licensed spectrum to unlicensed and shared spectrum.Spectrum sharing enables operators to opportunistically aggregatespectrums to dynamically support high-bandwidth services. Spectrumsharing can extend the benefit of NR technologies to operating entitiesthat may not have access to a licensed spectrum.

In some wireless communications systems, a UE and a base station maycommunicate over a communication link using a directional beam. Changesin the radio environment between the UE and the base station may degradethe quality of the beam used by the UE and the base station, which mayresult in communication failures between the UE and a serving cell(e.g., primary cell (Pcell), secondary cell (Scell), or both). The UEmay attempt to perform a beam failure recovery (BFR) procedure tore-establish connection with the serving cell. Additionally, in somewireless communications systems a UE may be in communication with morethan one transmission-reception point (TRP) (e.g., in a multi-TRPconfiguration) of a serving cell. Each of the more than one TRP maytransmit downlink transmissions to the UE according to a beamconfiguration and the UE may decode the downlink transmissions from eachof the more than one TRPs according to the beam configurations.Efficient detection and recovery from beam failures in multi-TRPconfigurations may help enhance multi-TRP communications.

BRIEF SUMMARY OF SOME EXAMPLES

The following summarizes some aspects of the present disclosure toprovide a basic understanding of the discussed technology. This summaryis not an extensive overview of all contemplated features of thedisclosure and is intended neither to identify key or critical elementsof all aspects of the disclosure nor to delineate the scope of any orall aspects of the disclosure. Its sole purpose is to present someconcepts of one or more aspects of the disclosure in summary form as aprelude to the more detailed description that is presented later.

In some aspects, a method of wireless communication performed by a userequipment (UE) includes receiving, from a base station (BS), acommunication indicating a beam failure configuration for a servingcell, the beam failure configuration including at least one of a beamfailure parameter of a beam group or a beam failure parameter of a cell;and detecting, in the serving cell based at least in part on the beamfailure configuration, a beam failure. The beam failure configuration isdetermined based on various rules that control the operation of the BFR.

In some aspects, a UE includes a memory; a processor coupled to thememory; and a transceiver coupled to the processor and configured toreceive, from a base station (BS), a communication indicating a beamfailure configuration for a serving cell, the beam failure configurationincluding at least one of a beam failure parameter of a beam group or abeam failure parameter of a cell, wherein the processor is configured todetect, in the serving cell based at least in part on the beam failureconfiguration, a beam failure.

In some aspects, a non-transitory computer-readable medium havingprogram code recorded thereon for operation by a UE is provided, theprogram code including code for causing a UE to receive, from a basestation (BS), a communication indicating a beam failure configurationfor a serving cell, the beam failure configuration including at leastone of a beam failure parameter of a beam group or a beam failureparameter of a cell; and code for causing the UE to detect, in theserving cell based at least in part on the beam failure configuration, abeam failure.

In some aspects, a UE includes means for receiving, from a base station(BS), a communication indicating a beam failure configuration for aserving cell, the beam failure configuration including at least one of abeam failure parameter of a beam group or a beam failure parameter of acell; and means for detecting, in the serving cell based at least inpart on the beam failure configuration, a beam failure.

Other aspects, features, and embodiments of the present invention willbecome apparent to those of ordinary skill in the art, upon reviewingthe following description of specific, exemplary embodiments of thepresent invention in conjunction with the accompanying figures. Whilefeatures of the present invention may be discussed relative to certainembodiments and figures below, all embodiments of the present inventioncan include one or more of the advantageous features discussed herein.In other words, while one or more embodiments may be discussed as havingcertain advantageous features, one or more of such features may also beused in accordance with the various embodiments of the inventiondiscussed herein. In similar fashion, while exemplary embodiments may bediscussed below as device, system, or method embodiments it should beunderstood that such exemplary embodiments can be implemented in variousdevices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a wireless communication network according to someaspects of the present disclosure.

FIG. 2A illustrates an example of a portion of a wireless communicationsystem that supports beam failure recovery techniques for multipletransmission-reception points (TRPs) in a primary or secondary cellaccording to some aspects of the present disclosure.

FIG. 2B illustrates aspects of beam failure recovery according to someaspects of the present disclosure.

FIG. 3A illustrates an example of a process flow that supports beamfailure recover techniques for multiple transmission-reception pointsaccording to some aspects of the present disclosure.

FIG. 3B illustrates an example of a process flow that supports beamfailure recovery techniques for multiple transmission-reception pointsaccording to some aspects of the present disclosure.

FIG. 3C further illustrates aspects of beam failure recovery accordingto some aspects of the present disclosure.

FIG. 4 is a block diagram of a user equipment (UE) according to someaspects of the present disclosure.

FIG. 5 is a block diagram of an exemplary base station (BS) according tosome aspects of the present disclosure.

FIG. 6 illustrates a flow diagram of a communication method according tosome aspects of the present disclosure.

FIG. 7 illustrates a flow diagram of a communication method according tosome aspects of the present disclosure.

FIG. 8 illustrates an example determination of a beam failureconfiguration according to some aspects of the present disclosure.

FIGS. 9A through 9D illustrate some beam failure configuration optionsaccording to some aspects of the present disclosure.

FIG. 10 a flow diagram of a communication method according to someaspects of the present disclosure.

FIG. 11 a flow diagram of a communication method according to someaspects of the present disclosure.

FIG. 12 a flow diagram of a communication method according to someaspects of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with theappended drawings, is intended as a description of variousconfigurations and is not intended to represent the only configurationsin which the concepts described herein may be practiced. The detaileddescription includes specific details for the purpose of providing athorough understanding of the various concepts. However, it will beapparent to those skilled in the art that these concepts may bepracticed without these specific details. In some instances, well-knownstructures and components are shown in block diagram form in order toavoid obscuring such concepts.

This disclosure relates generally to wireless communications systems,also referred to as wireless communications networks. In variousembodiments, the techniques and apparatus may be used for wirelesscommunication networks such as code division multiple access (CDMA)networks, time division multiple access (TDMA) networks, frequencydivision multiple access (FDMA) networks, orthogonal FDMA (OFDMA)networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, GlobalSystem for Mobile Communications (GSM) networks, 5^(th) Generation (5G)or new radio (NR) networks, as well as other communications networks. Asdescribed herein, the terms “networks” and “systems” may be usedinterchangeably.

An OFDMA network may implement a radio technology such as evolved UTRA(E-UTRA), Institute of Electrical and Electronics Engineers (IEEE)802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and the like. UTRA, E-UTRA,and GSM are part of universal mobile telecommunication system (UMTS). Inparticular, long term evolution (LTE) is a release of UMTS that usesE-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documentsprovided from an organization named “3rd Generation Partnership Project”(3GPP), and cdma2000 is described in documents from an organizationnamed “3rd Generation Partnership Project 2” (3GPP2). These variousradio technologies and standards are known or are being developed. Forexample, the 3rd Generation Partnership Project (3GPP) is acollaboration between groups of telecommunications associations thataims to define a globally applicable third generation (3G) mobile phonespecification. 3GPP long term evolution (LTE) is a 3GPP project whichwas aimed at improving the UMTS mobile phone standard. The 3GPP maydefine specifications for the next generation of mobile networks, mobilesystems, and mobile devices. The present disclosure is concerned withthe evolution of wireless technologies from LTE, 4G, 5G, NR, and beyondwith shared access to wireless spectrum between networks using acollection of new and different radio access technologies or radio airinterfaces.

In particular, 5G networks contemplate diverse deployments, diversespectrum, and diverse services and devices that may be implemented usingan OFDM-based unified, air interface. In order to achieve these goals,further enhancements to LTE and LTE-A are considered in addition todevelopment of the new radio technology for 5G NR networks. The 5G NRwill be capable of scaling to provide coverage (1) to a massive Internetof things (IoTs) with a Ultra-high density (e.g., ˜1M nodes/km²),ultra-low complexity (e.g., ˜10 s of bits/sec), ultra-low energy (e.g.,˜10+ years of battery life), and deep coverage with the capability toreach challenging locations; (2) including mission-critical control withstrong security to safeguard sensitive personal, financial, orclassified information, ultra-high reliability (e.g., ˜99.9999%reliability), ultra-low latency (e.g., ˜1 ms), and users with wideranges of mobility or lack thereof; and (3) with enhanced mobilebroadband including extreme high capacity (e.g., ˜10 Tbps/km²), extremedata rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates),and deep awareness with advanced discovery and optimizations.

The 5G NR may be implemented to use optimized OFDM-based waveforms withscalable numerology and transmission time interval (TTI); having acommon, flexible framework to efficiently multiplex services andfeatures with a dynamic, low-latency time division duplex(TDD)/frequency division duplex (FDD) design; and with advanced wirelesstechnologies, such as massive multiple input, multiple output (MIMO),robust millimeter wave (mmWave) transmissions, advanced channel coding,and device-centric mobility. Scalability of the numerology in 5G NR,with scaling of subcarrier spacing, may efficiently address operatingdiverse services across diverse spectrum and diverse deployments. Forexample, in various outdoor and macro coverage deployments of less than3 GHz FDD/TDD implementations, subcarrier spacing may occur with 15 kHz,for example over 5, 10, 20 MHz, and the like bandwidth (BW). For othervarious outdoor and small cell coverage deployments of TDD greater than3 GHz, subcarrier spacing may occur with 30 kHz over 80/100 MHz BW. Forother various indoor wideband implementations, using a TDD over theunlicensed portion of the 5 GHz band, the subcarrier spacing may occurwith 60 kHz over a 160 MHz BW. Finally, for various deploymentstransmitting with mmWave components at a TDD of 28 GHz, subcarrierspacing may occur with 120 kHz over a 500 MHz BW.

The scalable numerology of the 5G NR facilitates scalable TTI fordiverse latency and quality of service (QoS) requirements. For example,shorter TTI may be used for low latency and high reliability, whilelonger TTI may be used for higher spectral efficiency. The efficientmultiplexing of long and short TTIs to allow transmissions to start onsymbol boundaries. 5G NR also contemplates a self-contained integratedsubframe design with uplink/downlink scheduling information, data, andacknowledgement in the same subframe. The self-contained integratedsubframe supports communications in unlicensed or contention-basedshared spectrum, adaptive uplink/downlink that may be flexiblyconfigured on a per-cell basis to dynamically switch between UL anddownlink to meet the current traffic needs.

Each frame may include multiple consecutively numbered subframes orslots, and each subframe or slot may have the same duration. In someexamples, a frame may be divided (e.g., in the time domain) intosubframes, and each subframe may be further divided into a number ofslots. Alternatively, each frame may include a variable number of slots,and the number of slots may depend on subcarrier spacing. Each slot mayinclude a number of symbol periods (e.g., depending on the length of thecyclic prefix prepended to each symbol period). In some wirelesscommunications systems 100, a slot may further be divided into multiplemini-slots containing one or more symbols. Excluding the cyclic prefix,each symbol period may contain one or more (e.g., N_(f)) samplingperiods. The duration of a symbol period may depend on the subcarrierspacing or frequency band of operation.

A subframe, a slot, a mini-slot, or a symbol may be the smallestscheduling unit (e.g., in the time domain) of the wirelesscommunications system 100 and may be referred to as a transmission timeinterval (TTI). In some examples, the TTI duration (e.g., the number ofsymbol periods in a TTI) may be variable. Additionally, oralternatively, the smallest scheduling unit of the wirelesscommunications system 100 may be dynamically selected (e.g., in burstsof shortened TTIs (sTTIs)).

Various other aspects and features of the disclosure are furtherdescribed below. It should be apparent that the teachings herein may beembodied in a wide variety of forms and that any specific structure,function, or both being disclosed herein is merely representative andnot limiting. Based on the teachings herein one of an ordinary level ofskill in the art should appreciate that an aspect disclosed herein maybe implemented independently of any other aspects and that two or moreof these aspects may be combined in various ways. For example, anapparatus may be implemented or a method may be practiced using anynumber of the aspects set forth herein. In addition, such an apparatusmay be implemented or such a method may be practiced using otherstructure, functionality, or structure and functionality in addition toor other than one or more of the aspects set forth herein. For example,a method may be implemented as part of a system, device, apparatus,and/or as instructions stored on a computer readable medium forexecution on a processor or computer. Furthermore, an aspect maycomprise at least one element of a claim.

In some wireless communications systems, a user equipment (UE) maysupport communications with a serving cell via multiple beam groups. Insome instances, each beam group may be associated with one or moretransmission-reception points (TRPs), one or more beam directions,and/or one or more other spatial beam parameters. The UE may receivedownlink transmissions (e.g., via a physical downlink shared channel(PDSCH)) from multiple TRPs. Additionally, the UE may decode each of thedownlink transmissions according to a beam configuration associated withthe downlink transmission. Further, such multi beam group communicationsmay be primary cell (Pcell) communications, secondary cell (Scell)communications, or both. In some cases, one or more beams from aparticular beam group may degrade to a point where effectivecommunication via the beam is unlikely. Thus, beam failure detection(BFD), beam failure recovery (BFR), radio link monitoring (RLM), and/orradio link failure (RLF) recovery in such cases may be beneficial tohelp communications. In cases where multiple beam groups are used forcommunications, techniques such as discussed herein may be used toidentify a communication failure (e.g., beam failure and/or RLF) in aserving cell and/or recover from the communication failure based on abeam failure parameter of a beam group (e.g., TRP), a beam failureparameter of the cell, or both a beam failure parameter of a beam groupand a beam failure parameter of the cell.

In some cases, a UE may establish a connection with a Pcell and a Scell,where the Scell, and in some cases the Pcell, uses beamformedcommunications via two or more beam groups (e.g., transmission-receptionpoints (TRPs)). In some cases, the different beam groups may beassociated with different control resource set (CORESET) pool indexvalues, and one or more component carriers (CCs) may be configured withmultiple CORESET pool index values. Thus, from the perspective of theUE, different TRPs are transparent, and the UE can identify differentCORESET pool index values associated with received signals.

In some cases, the UE may perform BFD procedures that may identify oneor more beams associated with a particular CORESET pool index value thathave a degraded channel quality. In some cases, reference signalstransmitted via each of the TRPs (e.g., for BFD or for candidate beamdetection (CBD)) may provide an indication of a corresponding CORESETpool index (e.g., based on a reference signal sequence), which may bedetected at the UE. In some cases, the UE may determine to declare abeam failure for one or more beams, and may initiate a beam failurerecovery (BFR) in response. In some cases, a BFR MAC-CE containinginformation regarding the beam group and beam failure, as discussedfurther below, is provided.

In operation, the UE in the serving cell may operate with per-beam groupbeam failure detection and/or recovery parameters, cell-level beamfailure detection and/or recovery parameters, or a combination ofper-beam group and cell-level beam failure detection and/or recoveryparameters. Accordingly, in some instances a UE may perform BFD based onper-beam group BFD parameters or based on cell-level BFD parameters.Similarly, in some instances the UE may perform BFR based on per-beamgroup BFR parameters or based on cell-level BFR parameters. Therefore,in some instances the UE may perform BFD based on per-beam group BFDparameters and perform BFR based on cell-level BFR parameters, or viceversa (perform BFD based on cell-level BFD parameters and perform BFRbased on per-beam group BFR parameters). The per-beam group and/or thecell-level BFD and/or BFR parameters may be dynamically configured(e.g., by a serving cell, BS, UE, or otherwise), predefined (e.g., bynetwork operator, serving cell, BS, UE, standard provisions, orotherwise), or a combination of dynamically configured and predefined.Aspects of the present disclosure provide mechanisms for the deploymentof beam group BFD and/or BFR parameters in a serving cell along withcell-level BFD, BFR, RLM, and/or RLF parameters. In this regard, aspectsof the present disclosure can define the configuration/operationalrelationship between TRP-specific BFD/BFR and existing cell-levelBFD/BFR and RLM/RLF, including between TRP-specific BFD/BFR andSpCell/SCell BFD/BFR and between TRP-specific BFD/BFR and SpCell RLM/RLFon the same SpCell.

FIG. 1 illustrates a wireless communication network 100 according tosome aspects of the present disclosure. The network 100 may be a 5Gnetwork. The network 100 includes a number of base stations (BSs) 105(individually labeled as 105 a, 105 b, 105 c, 105 d, 105 e, and 105 f)and other network entities. A BS 105 may be a station that communicateswith UEs 115 and may also be referred to as an evolved node B (eNB), anext generation eNB (gNB), an access point, and the like. Each BS 105may provide communication coverage for a particular geographic area. In3GPP, the term “cell” can refer to this particular geographic coveragearea of a BS 105 and/or a BS subsystem serving the coverage area,depending on the context in which the term is used.

A BS 105 may provide communication coverage for a macro cell or a smallcell, such as a pico cell or a femto cell, and/or other types of cell. Amacro cell generally covers a relatively large geographic area (e.g.,several kilometers in radius) and may allow unrestricted access by UEswith service subscriptions with the network provider. A small cell, suchas a pico cell, would generally cover a relatively smaller geographicarea and may allow unrestricted access by UEs with service subscriptionswith the network provider. A small cell, such as a femto cell, wouldalso generally cover a relatively small geographic area (e.g., a home)and, in addition to unrestricted access, may also provide restrictedaccess by UEs having an association with the femto cell (e.g., UEs in aclosed subscriber group (CSG), UEs for users in the home, and the like).A BS for a macro cell may be referred to as a macro BS. A BS for a smallcell may be referred to as a small cell BS, a pico BS, a femto BS or ahome BS. In the example shown in FIG. 1 , the BSs 105 d and 105 e may beregular macro BSs, while the BSs 105 a-105 c may be macro BSs enabledwith one of three dimension (3D), full dimension (FD), or massive MIMO.The BSs 105 a-105 c may take advantage of their higher dimension MIMOcapabilities to exploit 3D beamforming in both elevation and azimuthbeamforming to increase coverage and capacity. The BS 105 f may be asmall cell BS which may be a home node or portable access point. A BS105 may support one or multiple (e.g., two, three, four, and the like)cells.

The network 100 may support synchronous or asynchronous operation. Forsynchronous operation, the BSs may have similar frame timing, andtransmissions from different BSs may be approximately aligned in time.For asynchronous operation, the BSs may have different frame timing, andtransmissions from different BSs may not be aligned in time.

The UEs 115 are dispersed throughout the wireless network 100, and eachUE 115 may be stationary or mobile. A UE 115 may also be referred to asa terminal, a mobile station, a subscriber unit, a station, or the like.A UE 115 may be a cellular phone, a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, atablet computer, a laptop computer, a cordless phone, a wireless localloop (WLL) station, or the like. In one aspect, a UE 115 may be a devicethat includes a Universal Integrated Circuit Card (UICC). In anotheraspect, a UE may be a device that does not include a UICC. In someaspects, the UEs 115 that do not include UICCs may also be referred toas IoT devices or internet of everything (IoE) devices. The UEs 115a-115 d are examples of mobile smart phone-type devices accessingnetwork 100. A UE 115 may also be a machine specifically configured forconnected communication, including machine type communication (MTC),enhanced MTC (eMTC), narrowband IoT (NB-IoT) and the like. The UEs 115e-115 h are examples of various machines configured for communicationthat access the network 100. The UEs 115 i-115 k are examples ofvehicles equipped with wireless communication devices configured forcommunication that access the network 100. A UE 115 may be able tocommunicate with any type of the BSs, whether macro BS, small cell, orthe like. In FIG. 1 , a lightning bolt (e.g., communication links)indicates wireless transmissions between a UE 115 and a serving BS 105,which is a BS designated to serve the UE 115 on the downlink (DL) and/oruplink (UL), desired transmission between BSs 105, backhaultransmissions between BSs, or sidelink transmissions between UEs 115.

In operation, the BSs 105 a-105 c may serve the UEs 115 a and 115 busing 3D beamforming and coordinated spatial techniques, such ascoordinated multipoint (CoMP) or multi-connectivity. The macro BS 105 dmay perform backhaul communications with the BSs 105 a-105 c, as well assmall cell, the BS 105 f. The macro BS 105 d may also transmitsmulticast services which are subscribed to and received by the UEs 115 cand 115 d. Such multicast services may include mobile television orstream video, or may include other services for providing communityinformation, such as weather emergencies or alerts, such as Amber alertsor gray alerts.

The BSs 105 may also communicate with a core network. The core networkmay provide user authentication, access authorization, tracking,Internet Protocol (IP) connectivity, and other access, routing, ormobility functions. At least some of the BSs 105 (e.g., which may be anexample of a gNB or an access node controller (ANC)) may interface withthe core network through backhaul links (e.g., NG-C, NG-U, etc.) and mayperform radio configuration and scheduling for communication with theUEs 115. In various examples, the BSs 105 may communicate, eitherdirectly or indirectly (e.g., through core network), with each otherover backhaul links (e.g., X1, X2, etc.), which may be wired or wirelesscommunication links.

The network 100 may also support mission critical communications withultra-reliable and redundant links for mission critical devices, such asthe UE 115 e, which may be a drone. Redundant communication links withthe UE 115 e may include links from the macro BSs 105 d and 105 e, aswell as links from the small cell BS 105 f. Other machine type devices,such as the UE 115 f (e.g., a thermometer), the UE 115 g (e.g., smartmeter), and UE 115 h (e.g., wearable device) may communicate through thenetwork 100 either directly with BSs, such as the small cell BS 105 f,and the macro BS 105 e, or in multi-step-size configurations bycommunicating with another user device which relays its information tothe network, such as the UE 115 f communicating temperature measurementinformation to the smart meter, the UE 115 g, which is then reported tothe network through the small cell BS 105 f. The network 100 may alsoprovide additional network efficiency through dynamic, low-latencyTDD/FDD communications, such as vehicle-to-vehicle (V2V),vehicle-to-everything (V2X), cellular-V2X (C-V2X) communications betweena UE 115 i, 115 j, or 115 k and other UEs 115, and/orvehicle-to-infrastructure (V2I) communications between a UE 115 i, 115j, or 115 k and a BS 105.

In some implementations, the network 100 utilizes OFDM-based waveformsfor communications. An OFDM-based system may partition the system BWinto multiple (K) orthogonal subcarriers, which are also commonlyreferred to as subcarriers, tones, bins, or the like. Each subcarriermay be modulated with data. In some instances, the subcarrier spacingbetween adjacent subcarriers may be fixed, and the total number ofsubcarriers (K) may be dependent on the system BW. The system BW mayalso be partitioned into subbands. In other instances, the subcarrierspacing and/or the duration of TTIs may be scalable.

In some aspects, the BSs 105 can assign or schedule transmissionresources (e.g., in the form of time-frequency resource blocks (RB)) fordownlink (DL) and uplink (UL) transmissions in the network 100. DLrefers to the transmission direction from a BS 105 to a UE 115, whereasUL refers to the transmission direction from a UE 115 to a BS 105. Thecommunication can be in the form of radio frames. A radio frame may bedivided into a plurality of subframes or slots, for example, about 10.Each slot may be further divided into mini-slots. In a FDD mode,simultaneous UL and DL transmissions may occur in different frequencybands. For example, each subframe includes a UL subframe in a ULfrequency band and a DL subframe in a DL frequency band. In a TDD mode,UL and DL transmissions occur at different time periods using the samefrequency band. For example, a subset of the subframes (e.g., DLsubframes) in a radio frame may be used for DL transmissions and anothersubset of the subframes (e.g., UL subframes) in the radio frame may beused for UL transmissions.

The DL subframes and the UL subframes can be further divided intoseveral regions. For example, each DL or UL subframe may havepre-defined regions for transmissions of reference signals, controlinformation, and data. Reference signals are predetermined signals thatfacilitate the communications between the BSs 105 and the UEs 115. Forexample, a reference signal can have a particular pilot pattern orstructure, where pilot tones may span across an operational BW orfrequency band, each positioned at a pre-defined time and a pre-definedfrequency. For example, a BS 105 may transmit cell specific referencesignals (CRSs) and/or channel state information-reference signals(CSI-RSs) to enable a UE 115 to estimate a DL channel. Similarly, a UE115 may transmit sounding reference signals (SRSs) to enable a BS 105 toestimate a UL channel. Control information may include resourceassignments and protocol controls. Data may include protocol data and/oroperational data. In some aspects, the BSs 105 and the UEs 115 maycommunicate using self-contained subframes. A self-contained subframemay include a portion for DL communication and a portion for ULcommunication. A self-contained subframe can be DL-centric orUL-centric. A DL-centric subframe may include a longer duration for DLcommunication than for UL communication. A UL-centric subframe mayinclude a longer duration for UL communication than for ULcommunication.

In some aspects, the network 100 may be an NR network deployed over alicensed spectrum. The BSs 105 can transmit synchronization signals(e.g., including a primary synchronization signal (PSS) and a secondarysynchronization signal (SSS)) in the network 100 to facilitatesynchronization. The BSs 105 can broadcast system information associatedwith the network 100 (e.g., including a master information block (MIB),remaining system information (RMSI), and other system information (OSI))to facilitate initial network access. In some instances, the BSs 105 maybroadcast the PSS, the SSS, and/or the MIB in the form ofsynchronization signal block (SSBs) over a physical broadcast channel(PBCH) and may broadcast the RMSI and/or the OSI over a physicaldownlink shared channel (PDSCH).

In some aspects, a UE 115 attempting to access the network 100 mayperform an initial cell search by detecting a PSS from a BS 105. The PSSmay enable synchronization of period timing and may indicate a physicallayer identity value. The UE 115 may then receive a SSS. The SSS mayenable radio frame synchronization, and may provide a cell identityvalue, which may be combined with the physical layer identity value toidentify the cell. The PSS and the SSS may be located in a centralportion of a carrier or any suitable frequencies within the carrier.

After receiving the PSS and SSS, the UE 115 may receive a MIB. The MIBmay include system information for initial network access and schedulinginformation for RMSI and/or OSI. After decoding the MIB, the UE 115 mayreceive RMSI and/or OSI. The RMSI and/or OSI may include radio resourcecontrol (RRC) information related to random access channel (RACH)procedures, paging, control resource set (CORESET) for physical downlinkcontrol channel (PDCCH) monitoring, physical UL control channel (PUCCH),physical UL shared channel (PUSCH), power control, and SRS.

Physical channels may be multiplexed on a carrier according to varioustechniques. A physical control channel and a physical data channel maybe multiplexed on a downlink carrier, for example, using one or more oftime division multiplexing (TDM) techniques, frequency divisionmultiplexing (FDM) techniques, hybrid TDM-FDM techniques, or spatialdivision multiplexing (SDM). A control region (e.g., a control resourceset (CORESET)) for a physical control channel may be defined by a numberof symbol periods and may extend across the system bandwidth or a subsetof the system bandwidth of the carrier. One or more control regions(e.g., CORESETs) may be configured for a set of the UEs 115. Forexample, one or more of the UEs 115 may monitor or search controlregions for control information according to one or more search spacesets, and each search space set may include one or multiple controlchannel candidates in one or more aggregation levels arranged in acascaded manner. An aggregation level for a control channel candidatemay refer to a number of control channel resources (e.g., controlchannel elements (CCEs)) associated with encoded information for acontrol information format having a given payload size. Search spacesets may include common search space sets configured for sending controlinformation to multiple UEs 115 and UE-specific search space sets forsending control information to a specific UE 115

After obtaining the MIB, the RMSI and/or the OSI, the UE 115 can performa random access procedure to establish a connection with the BS 105. Insome examples, the random access procedure may be a four-step randomaccess procedure. For example, the UE 115 may transmit a random accesspreamble and the BS 105 may respond with a random access response. Therandom access response (RAR) may include a detected random accesspreamble identifier (ID) corresponding to the random access preamble,timing advance (TA) information, a UL grant, a temporary cell-radionetwork temporary identifier (C-RNTI), and/or a backoff indicator. Uponreceiving the random access response, the UE 115 may transmit aconnection request to the BS 105 and the BS 105 may respond with aconnection response. The connection response may indicate a contentionresolution. In some examples, the random access preamble, the RAR, theconnection request, and the connection response can be referred to asmessage 1 (MSG1), message 2 (MSG2), message 3 (MSG3), and message 4(MSG4), respectively. In some examples, the random access procedure maybe a two-step random access procedure, where the UE 115 may transmit arandom access preamble and a connection request in a single transmissionand the BS 105 may respond by transmitting a random access response anda connection response in a single transmission.

After establishing a connection, the UE 115 and the BS 105 can enter anormal operation stage, where operational data may be exchanged. Forexample, the BS 105 may schedule the UE 115 for UL and/or DLcommunications. The BS 105 may transmit UL and/or DL scheduling grantsto the UE 115 via a PDCCH. The scheduling grants may be transmitted inthe form of DL control information (DCI). The BS 105 may transmit a DLcommunication signal (e.g., carrying data) to the UE 115 via a PDSCHaccording to a DL scheduling grant. The UE 115 may transmit a ULcommunication signal to the BS 105 via a PUSCH and/or PUCCH according toa UL scheduling grant.

In some aspects, the BS 105 may communicate with a UE 115 using hybridautomatic repeat request (HARQ) techniques to improve communicationreliability, for example, to provide an ultra-reliable low-latencycommunication (URLLC) service. The BS 105 may schedule a UE 115 for aPDSCH communication by transmitting a DL grant in a PDCCH. The BS 105may transmit a DL data packet to the UE 115 according to the schedule inthe PDSCH. The DL data packet may be transmitted in the form of atransport block (TB). If the UE 115 receives the DL data packetsuccessfully, the UE 115 may transmit a HARQ acknowledgement (ACK) tothe BS 105. Conversely, if the UE 115 fails to receive the DLtransmission successfully, the UE 115 may transmit a HARQnegative-acknowledgement (NACK) to the BS 105. Upon receiving a HARQNACK from the UE 115, the BS 105 may retransmit the DL data packet tothe UE 115. The retransmission may include the same coded version of DLdata as the initial transmission. Alternatively, the retransmission mayinclude a different coded version of the DL data than the initialtransmission. The UE 115 may apply soft-combining to combine the encodeddata received from the initial transmission and the retransmission fordecoding. The BS 105 and the UE 115 may also apply HARQ for ULcommunications using substantially similar mechanisms as the DL HARQ.

In some aspects, the network 100 may operate over a system BW or acomponent carrier (CC) BW. The network 100 may partition the system BWinto multiple BWPs (e.g., portions). A BS 105 may dynamically assign aUE 115 to operate over a certain BWP (e.g., a certain portion of thesystem BW). The assigned BWP may be referred to as the active BWP. TheUE 115 may monitor the active BWP for signaling information from the BS105. The BS 105 may schedule the UE 115 for UL or DL communications inthe active BWP. In some aspects, a BS 105 may assign a pair of BWPswithin the CC to a UE 115 for UL and DL communications. For example, theBWP pair may include one BWP for UL communications and one BWP for DLcommunications.

In some aspects, the network 100 may operate over a shared channel,which may include shared frequency bands or unlicensed frequency bands.For example, the network 100 may be an NR-unlicensed (NR-U) network. TheBSs 105 and the UEs 115 may be operated by multiple network operatingentities. To avoid collisions, the BSs 105 and the UEs 115 may employ alisten-before-talk (LBT) procedure to monitor for transmissionopportunities (TXOPs) in the shared channel. For example, a transmittingnode (e.g., a BS 105 or a UE 115) may perform an LBT prior totransmitting in the channel. When the LBT passes, the transmitting nodemay proceed with the transmission. When the LBT fails, the transmittingnode may refrain from transmitting in the channel. In an example, theLBT may be based on energy detection. For example, the LBT results in apass when signal energy measured from the channel is below a threshold.Conversely, the LBT results in a failure when signal energy measuredfrom the channel exceeds the threshold. In another example, the LBT maybe based on signal detection. For example, the LBT results in a passwhen a channel reservation signal (e.g., a predetermined preamblesignal) is not detected in the channel. In some aspects, the network 100may utilize an FBE-based contention scheme for sharing a radio channelamong multiple BSs 105 and/or UEs 115 of different network operatingentities and/or different radio access technologies (RATs).

FIG. 2A illustrates an example of a wireless communications system 200that supports beam failure recovery techniques for multipletransmission-reception points (TRPs) in serving cell 210 (Pcell and/orScell) in accordance with aspects of the present disclosure. Asdiscussed above, the multiple TRPs illustrated in FIG. 2A is an exampleof multiple beam groups. In some examples, wireless communicationssystem 200 may implement aspects of wireless communications system 100.Wireless communications system 200 may include a UE 205 and incommunications with a number of TRPs 215, which may be examples of thecorresponding devices described herein. TRPs 215 may, in this example,provide a multi-TRP serving cell, for example, in which a first beam220-a of a first TRP 215-a and a second beam 220-b of a second TRP 215-bprovide communications with the UE 205.

In some cases, the multi-TRP transmissions may be configured based on asingle downlink control information (DCI) communication. In some cases,the multi-TRP transmissions may be configured based on multiple downlinkcontrol information m(DCI) communications, in which a first DCI (e.g.,transmitted in PDCCH1 from first TRP 215-a) schedules a downlink sharedchannel transmission (e.g., PDSCH1 transmitted from first TRP 215-a viafirst beam 220-a), and a second DCI (e.g., transmitted in PDCCH2 fromsecond TRP 215-b) schedules a second downlink shared channeltransmission (e.g., PDSCH2 transmitted from second TRP 215-b via secondbeam 220-b). TRP 215 differentiation at the UE 205, in some cases, maybe based on a value of a CORESET pool index (e.g., CORESETPoolIndex),where each CORESET (e.g., up to a maximum of five CORESETs) can beconfigured with a value of CORESET pool index. In some cases, the valueof CORESET pool index can be zero or one, which groups the CORESETs intotwo groups that may correspond to the different TRPs 215. Only some CCsmay be configured with two values of CORESET pool index, while other CCsmay not be configured with two values of CORESET pool index and thusBFD/BFR for on a per-TRP 215 basis may be provided for CCs that areconfigured with two values of CORESET pool index.

In some cases, the UE 205 may be configured to provide per-TRP 215 BFR,which enables separate BFD and separate CBD for the beams correspondingto a TRP 215 in a CC that is configured with two values of CORESET poolindex. In the absence of per-TRP 215 BFR, beam failure detection andbeam candidate determination may not be triggered until all beams inthat CC become weak. With per-TRP 215 BFR, when beams for a given TRPbecome weak, recovery procedures can be done and a best beamcorresponding to that TRP 215 can be identified without having to waitfor the beams of the other TRP 215 to also become weak, and thusreliability and communications efficiency can be enhanced. In theexample, of FIG. 2A, serving cell 210 may be configured with two valuesof CORESET pool index, with one value associated with the first TRP215-a and a second value associated with second TRP 215-b. In this case,each TRP 215 may transmit one or more BFD reference signals that may bemonitored by the UE 205. In this example, the UE 205 may determine thatthe first beam 220-a of the first CORESET pool index value has a channelmetric (e.g., a reference signal received power RSRP)) that is below athreshold value (e.g., when radio link quality is worse than a thresholdQ_(out) for reference signals in BFD reference signal that areassociated with CORESET pool index value) for a period of time. Variousexamples of beam failure declaration, candidate beam detection, and beamrecovery are discussed further below.

FIG. 2B illustrates an example sequence 230 that illustrates beamfailure detection (BFD) and beam failure recovery (BFR) in a system suchas that illustrated in FIG. 2A. As illustrated in FIG. 2B, TRP set q0232 is providing communications. As illustrated, set q0 includes two TRPreference signals (RS), indicating two communicating beams. Forinstance, the TRP set q0 232 are reference signals transmitted by theTRP 215-a and/or the TRP 215-b and monitored and measured by the UE 205for BFD. In step 236, the level of one or more of the TRP resources inset 232 is measured and determined to be below a threshold value Qout,resulting in provision of an out-of-sync (OOS) indication. In step 238,in response to the OOS indication, a beam failure detector (BFD) timeris started and a beam failure index (BFI) count is set to 1. However, asindicated in FIG. 2B, BFD timer 240 times out prior to receipt ofanother OOS indication.

In step 242 the level of one or more of the TRP resources in set 232 ismeasured and determined to be below a configurable threshold value Qoutresulting in provision of an OOS indication. As before, in step 244 aBFD timer 246 is started and a BFI counter initiated. As is illustratedin FIG. 2B in step 248, one or more of the TRP resources in set 232 isagain measured and determined to be below a threshold value Qoutresulting in provision of another OOS indication that occurs within BFDtimer 246. In step 250, the BFI counter is incremented until the BFIcounter is at a MaxCnt value. In this particular example, MaxCnt is setto 2, however MaxCnt can be configurably set to any integer such that ifthe TRP resources result in OOS indication for set period of time.

In step 250, with BFI counter at the MaxCnt value, a BFR timer 252 isstarted. In step 254, a reference signal received power (RSRP)corresponding to the TRP RS q1 234 is measured to have a value greaterthan the threshold. In step 256, a report is received from step 254 anda request for the TRP resource in set 234 is presented. In step 260, arandom access procedure on a Random Access Channel (RACH) can betriggered and in step 258 the RACH request can be sent, for example to aprimary cell (PCell) receiver of the request. Transmission of the RACHmessage can trigger a response window 272. Within the first timingwindow, a PDCCH 262 can be received that stops the BFR timer 264 withinthe time-out period of the response window 272 or a PDCCH 266 that stopsBFR 268 after the response window time out but before the BFR timer 252timeout will result in adaption of the TRP resource from set q1 234.However, if step 270 is reached, the BFR times out and results inoverall failure to recover in step 270.

FIG. 3A illustrates an example of a process flow 300 that supports beamfailure recovery techniques for multiple beam groups in a serving cellin accordance with aspects of the present disclosure. In some examples,process flow 300 may implement aspects of wireless communications system100 or 200 and further illustrates aspects of the process flow 230 ofFIG. 2B. Process flow 300 may be implemented by a UE 310 and a PCell 305that has two values of CORESET pool index values (and is served bymultiple different beam groups) as described herein. In the followingdescription of the process flow 300, the communications between the UE310 and the Pcell 305 may be transmitted in a different order than theexample order shown, or the operations performed by the UE 310 and Pcell305 may be performed in different orders or at different times. Someoperations may also be omitted from the process flow 300, and otheroperations may be added to the process flow 300.

In some examples, the operations illustrated in process flow 300 may beperformed by hardware (e.g., including circuitry, processing blocks,logic components, and other components), code (e.g., software orfirmware) executed by a processor, or any combination thereof.Alternative examples of the following may be implemented, where somesteps are performed in a different order than described or are notperformed at all. In some cases, steps may include additional featuresnot mentioned below, or further steps may be added.

At message 315, the Pcell 305 may transmit, and UE 310 may receive, oneor more BFD reference signals of a set of BFD reference signals. In thisregard, the UE 310 may be monitoring for the BFD reference signals basedon a beam group BFD parameter or a cell-level BFD parameter. The UE 310may measure one or more channel metrics of the BFD reference signals aspart of a BFD. In accordance with various aspects, the BFD referencesignals may be transmitted by different beam groups, and have multipleCORESET pool index values, and the BFD reference signals have anindication of the associated CORESET pool index value (e.g., zero orone, based on a reference signal sequence that is configured to aCORESET pool index value).

At step 320, the UE 310 may determine that a BFD is detected (e.g., asdiscussed above in FIG. 2B). In some cases, the detection of the BFD maybe based on a channel metric of the reference signal being below athreshold value (e.g., Q_(out)). In some cases, the BFD may be based onperiodic CSI-RS resources configured by RRC (e.g., configured by RRCparameter failureDetectionResources). In some cases, the BFD referencesignals may include up to two reference signals on a single port. Insome instances, if the BFD reference signals are not configured, thereference signal sets indicated by the active TCI states of CORESETsmonitored by the UE 310 may be used. If, for an active TCI state of aCORESET, there are multiple reference signal indices, the one withQCL-TypeD is preferentially used. Otherwise, QCL-TypeA, QCL-TypeB, orQCL-TypeC can be used. The physical layer in the UE 310 may assess theradio link quality according to the BFD set against the threshold value(e.g., Q_(out)). In some instances, if radio link quality is worse thanQ_(out) for all the reference signals in the BFD resource set, then theUE 310 may declare a beam failure.

At step 325, the UE 310 may perform candidate beam detection (CBD). Insome cases, CBD may be based on periodic CSI-RS/SSB that are configuredby RRC (e.g., configured by RRC parameter candidateBeamRSList). In somecases, up to 16 resources with the corresponding random access preambleindex (e.g., ra-preamble-index) may be configured. The UE 310 mayprovide reference signal indices and the RSRP among the list that haveequal or larger RSRP value than a threshold value (e.g., Q_(in)), whichmay be a configurable threshold.

At communications 330, the UE 310 may initiate a BFR based on a beamgroup BFD parameter or a cell-level BFD parameter. For example, in someinstances the UE 310 may transmit a RACH request to the Pcell 305. Insome cases, the UE 310 may initiate random access procedures (e.g.,contention-free random access) based on the random access resource(e.g., ra-preamble-index) associated with a selected reference signalindex with RSRP above the threshold (e.g., RS index q_new).

At communications 335, the Pcell 305 may transmit, and the UE 310 mayreceive, a BFR response based on a beam group BFD parameter or acell-level BFD parameter. In some cases, the UE 310 may monitor PDCCH ina search space set provided by a RRC parameter (e.g.,recoverySearchSpaceId) for detection of a DCI format with CRC scrambledby C-RNTI or MCS-C-RNTI starting from slot n+4. If the UE 310 receivesthe PDCCH within this window, BFR is completed. Following the BFRresponse, the UE 310 may use quasi co-located (QCL) RS assumptions thatthe same QCL parameters as associated with reference signal index q_newuntil the UE 310 receives an activation for a TCI state. In some cases,after a set of symbols (e.g., 28 symbols) from a last symbol of a firstPDCCH reception where the UE 310 detects a DCI format with CRC scrambledby C-RNTI or MCS-C-RNTI, the UE 310 assumes the same QCL parameters asthe ones associated with RS index q_new for PDCCH monitoring in aCORESET with index 0.

In some cases, Pcell 310 may be configured with multiple beam groups(e.g., TRPs), and the CORESET pool index may be configured with multiplevalues. In some cases, separate RACH resources may be configured fordifferent CORESET pool index values, which may allow the UE 310 toindicate beam failure associated with a particular CORESET pool indexvalue, which may be associated with a particular beam group. Asdiscussed herein, in some cases one or more Scells may be configuredwith multiple values of CORESET pool index, and a UE may perform aBFD/BFR for the Scell, an example of which is discussed with referenceto FIG. 3B.

FIG. 3B illustrates another example of a process flow 340 that supportsbeam failure recovery techniques for multiple beam groups in a secondarycell in accordance with aspects of the present disclosure. In someexamples, process flow 340 may implement aspects of wirelesscommunications system 100 or 200. Process flow 340 may be implemented bya UE 344 and a PCell 342 and a Scell 346, where the Scell 346 may havemultiple values of CORESET pool index values (and is served by multipledifferent TRPs) as described herein. In the following description of theprocess flow 340, the communications between the UE 344, the Pcell 342,and the Scell 346 may be transmitted in a different order than theexample order shown, or the operations performed by the UE 344, Pcell342, and Scell 346 may be performed in different orders or at differenttimes. Some operations may also be omitted from the process flow 340,and other operations may be added to the process flow 340.

In some examples, the operations illustrated in process flow 340 may beperformed by hardware (e.g., including circuitry, processing blocks,logic components, and other components), code (e.g., software orfirmware) executed by a processor, or any combination thereof.Alternative examples of the following may be implemented, where somesteps are performed in a different order than described or are notperformed at all. In some cases, steps may include additional featuresnot mentioned below, or further steps may be added.

At a high level, the UE 344 may monitor for BFD RS(s) from the Scell346, report a BFD of the Scell 346 to the Pcell 342, and perform a BFR(e.g., via a RACH procedure) for the Scell 346 via the Pcell 342.

At communications 348, the Scell 346 may transmit, and UE 344 mayreceive, one or more BFD reference signals of a set of BFD referencesignals. In this regard, the UE 344 may be monitoring for the BFDreference signals based on a beam group BFD parameter or a cell-levelBFD parameter. The UE 344 may measure one or more channel metrics of theBFD reference signals as part of a BFD process. In accordance withvarious aspects, the BFD reference signals may be transmitted bydifferent TRPs, and have multiple CORESET pool index values, and the BFDreference signals have an indication of the associated CORESET poolindex value (e.g., zero or one, based on a reference signal sequencethat is configured to a CORESET pool index value).

At step 350, the UE 344 may determine that a BFD is detected at theScell 346. In some cases, similarly as discussed with reference to FIGS.2B and 3A above, the detection of the BFD may be based on a channelmetric of the reference signal (the BFD RS(s) received at communication348) being below a threshold value (e.g., Q_(out)). In some cases, theBFD may be based on periodic CSI-RS resources configured by RRC (e.g.,configured by RRC parameter failureDetectionResources). In some cases,the BFD reference signals may include up to two reference signals on asingle port. If the BFD reference signals are not configured, thereference signal sets indicated by the active TCI states of CORESETsmonitored by the UE 344 may be used. If, for an active TCI state of aCORESET, there are multiple reference signal indices, the one withQCL-TypeD is preferentially used. Otherwise, QCL-TypeA, QCL-TypeB, orQCL-TypeC can be used. The physical layer in the UE 344 may assess theradio link quality according to the BFD set against the threshold value(e.g., Q_(out)). If radio link quality is worse than Q_(out) for all thereference signals in the BFD resource set, the UE 344 may declare a beamfailure.

In one example, two sets of failure detection resources may beconfigured, each corresponding to a different CORESET pool index value.In another example, each resource within the failure detection resourcesused to transmit the BFD reference signals may be configured with aCORESET pool index value. In some cases, if a resource is not configuredwith a CORESET pool index value, it is assumed to be associated withCORESET pool index value zero. In some cases, a BFD reference signalresource may be configured with both values of CORESET pool index, inwhich case the associated reference signal may be considered for bothTRPs. In some cases, when failure detection resources are notconfigured, reference signal sets indicated by the active TCI states ofCORESETs configured with CORESET pool index zero or one determines thefirst and second sets of resources, respectively. In some cases, a beamfailure for a value of CORESET pool index may be declared when radiolink quality is worse than the configured threshold value (e.g.,Q_(out)) for all the reference signals in the BFD resources that areassociated with that CORESET pool index value.

At communications 352, the UE 344 may initiate a BFR based on a beamgroup BFD parameter or a cell-level BFD parameter. For example, the UE344 may transmit a link recovery request (LRR) or other BFR request onthe Pcell 342. In some cases, the recovery request may be transmitted ona Pcell, on a primary Scell (Pscell), or on a Scell that is configuredfor PUCCH (a PUCCH-Scell) in which PUCCH BFR is configured. The LRR mayindicate that the UE 344 is requesting uplink resources (e.g., similarto a scheduling request (SR), and may use PUCCH format 0 or 1. In somecases, two PUCCH resources can be configured for LRR (e.g., indicated byschedulingRequestID-BFR-Scell) by two corresponding scheduling requestIDs. The PUCCH resources or scheduling request IDs may be associatedwith the values of CORESET pool index. If BFD is declared for a value ofCORESET pool index in Scell 346, in some cases, the PUCCHresource/scheduling request ID that corresponds to another value ofCORESET pool index may be used for LRR transmission. Such a selection ofresources provides that if the beams of Scell 346 and a PUCCH-cell arethe same, and if all beams for one TRP become weak, LRR can betransmitted using a beam corresponding to the other TRP. Such a rule maybe applied, for example, when the CC with PUCCH-BFR is in the same bandas the Scell 346.

In other cases, the PUCCH resource/scheduling request ID thatcorresponds to the same value of CORESET pool index is used for LRRtransmission. Such a selection may provide that LRR is transmitted tothe same TRP for non-ideal backhaul scenario. Such a rule may befollowed, for example, when separate feedback is configured fordifferent cells (ACKNACKFeedbackMode=SeparateFeedback). In other cases,the PUCCH resource/scheduling request ID that corresponds to CORESETpool index=0 is used for LRR transmission. Such a rule can be followed,for example, when the CC with PUCCH-BFR is in a different band than theScell 346. In still other cases, multiple PUCCH resources/schedulingrequest IDs may be used to transmit LRR irrespective of the CORESET poolindex for which BFD is declared. This means that multiple instances ofthe LRR transmission are provided across the multiple PUCCH resources(and transmitted to both TRPs).

At communication 354, the Pcell 342 may provide an uplink grant to theUE 344. Such an uplink grant may be a normal uplink grant withC-RNTI/MCS-C-RNTI that can serve as response to LRR, which the UE 344may use to transmit a PUSCH in which a BFRQ MAC-CE can be transmitted.It is noted that in some cases the UE 344 may have an existing uplinkgrant, in which cases the LRR and associated uplink grant operations maybe skipped.

At step 356, the UE 344 may perform a CBD procedure. Before sending theMAC-CE with the beam failure recovery message, the UE 344 may firstidentify one or more candidate beams for the failed Scell 346. The CBDprocess may be performed in a similar manner as discussed with referenceto FIG. 3A and FIG. 2B above, with the exception that the procedure isfor Scell 346. In some cases, up to 64 resources (e.g., indicated in RRCin candidateBeamRSSCellList-r16), which can be transmitted on the failedScell 346 or another CC in the same band. In some cases, each candidatebeam is associated with a CORESET pool index value. In one example, twolists of candidate beams may be provided (e.g., two lists for parametercandidateBeamRSSCellList-r16 are configured) each corresponding to aCORESET pool index value. In another example, each reference signal inthe list of candidate beams (e.g., in candidateBeamRSSCellList-r16) maybe configured with a CORESET pool index value. In some cases, if areference signal is not configured with a CORESET pool index value, itis assumed to be associated with CORESET pool index value zero. Inaddition, it can be allowed for a reference signal to be configured withboth values of CORESET pool index, in which case it is considered forboth TRPs. In some instances, when BFD is declared for a value ofCORESET pool index, a candidate beam may be identified only withinreference signals that are associated with the same value of CORESETpool index.

At communication 358, the UE 344 may transmit a beam failure recoverymessage in a BFR MAC-CE (a BFRQ). Examples of the BFR MAC-CE arediscussed further below. The BFR MAC-CE can be transmitted using theresources provided in the uplink grant, and can be sent on any cell,including failed SCell 346 in some instances. In some cases, the UE 344may indicate the CORESET pool index value in the Scell MAC-CE for thecorresponding Scell 346. Such an indication may be provided, in somecases, in accordance with the examples discussed further below.

At communication 360, the Pcell 342 may provide a BFR response to the UE344 based on a beam group BFD parameter or a cell-level BFD parameter.In some cases, the response may be an uplink grant to schedule a newtransmission (e.g., with a toggled new data indicator (NDI)) for thesame HARQ process as the PUSCH carrying the BFR MAC-CE. In some cases,if a new beam corresponding to a value of CORESET pool index in theScell 346 is reported in the BFR MAC-CE, after 28 symbols from the endof the BFR response (end of PDCCH), the UE 344 may use a QCL assumptionthat only the CORESETs with the same value of CORESET pool index arereset to the new beam (e.g., q_(new)) in the Scell 346. Assuming thatPUCCH resources are also associated with a value of CORESET pool index,spatial relation for only those PUCCH resources that are associated withthe same value of CORESET pool index are reset to the new beam in theScell 346 when the Scell 346 is a PUCCH-Scell. If PUCCH resources arenot associated with a value of CORESET pool index, and if BFR MAC-CEindicates BFD and candidate beams for both values of CORESET pool index(e.g., two q_(new) in the Scell 346), PUCCH beams are reset to thecandidate beam corresponding to CORESET pool index=0 (when Scell isPUCCH-Scell).

Thus, in some cases the UE 344 may reset the beams for one or more PUCCHresources associated with the same value as the CORESET pool index valueof the identified candidate beam, when the secondary cell is configuredfor uplink control information transmissions. Further, in some cases,the UE 344 may reset the beams for one or more PUCCH resources inresponse to the CORESET pool index value of the identified candidatebeam having a first value (e.g., CORESET pool index=0), and refrain fromresetting the beams for the one or more PUCCH resources in response tothe CORESET pool index value of the identified candidate beam having asecond value (e.g., CORESET pool index=1), when the secondary cell isconfigured for uplink control information transmissions.

FIG. 3C illustrates another example process flow 370 for beam failurerecovery techniques for multiple beam groups in a secondary cell inaccordance with aspects of the present disclosure. In some examples,process flow 370 may implement aspects of wireless communications system100 or 200. Process flow 370 may be implemented by a UE 372 and a Pcell374 and a Scell 376, where the Scell 376 may have multiple values ofCORESET pool index values (and is served by multiple different TRPs) asdescribed herein. In some aspects, the Pcell 372 may operate over acarrier frequency in a frequency range 1 (FR1), and the Scell 376 mayoperate over a carrier frequency in a frequency range 2 (FR2). FR1 mayrefer to sub-6 GHz frequencies (e.g., between about 4 GHz to about 7GHz), and FR2 may refer to mmWave frequencies (e.g., between about 24GHz to about 52 GHz). In the following description of the process flow370, the communications between the UE 372, the Pcell 374, and the Scell376 may be transmitted in a different order than the example ordershown, or the operations performed by the UE 372, Pcell 374, and Scell376 may be performed in different orders or at different times. Someoperations may also be omitted from the process flow 370, and otheroperations may be added to the process flow 370.

In some examples, the operations illustrated in process flow 340 may beperformed by hardware (e.g., including circuitry, processing blocks,logic components, and other components), code (e.g., software orfirmware) executed by a processor, or any combination thereof.Alternative examples of the following may be implemented, where somesteps are performed in a different order than described or are notperformed at all. In some cases, steps may include additional featuresnot mentioned below, or further steps may be added.

The process flow 370 may be substantially similar to the process flow340. For instance, the UE 344 may monitor for BFD RS(s) 377. from theScell 376 and report a BFD of the Scell 376 to the Pcell 374. However,in the process flow 370, the UE 372 may perform a RACH procedure withthe Scell 376 instead of the Pcell 374 to complete a BFR for the Scell376.

At step 378, the UE 372 may determine that a BFD is detected at theScell 376. In some cases, similarly as discussed with reference to FIGS.2B, 3A, and 3B above, the detection of the BFD may be based on a channelmetric of the reference signal (e.g., BFD RS(s) 377 received from theScell 376 as discussed above with respect to communication 348 of FIG.2B) being below a threshold value (e.g., Q_(out)). In some cases, theBFD may be based on periodic CSI-RS resources configured by RRC (e.g.,configured by RRC parameter failureDetectionResources). In some cases,the BFD reference signals may include up to two reference signals on asingle port. If the BFD reference signals are not configured, thereference signal sets indicated by the active TCI states of CORESETsmonitored by the UE 374 may be used. If, for an active TCI state of aCORESET, there are multiple reference signal indices, the one withQCL-TypeD is preferentially used. Otherwise, QCL-TypeA, QCL-TypeB, orQCL-TypeC can be used. The physical layer in the UE 374 may assess theradio link quality according to the BFD set against the threshold value(e.g., Q_(out)). If radio link quality is worse than Q_(out) for all thereference signals in the BFD resource set, the UE 374 may declare a beamfailure.

In one example, two sets of failure detection resources may beconfigured, each corresponding to a different CORESET pool index value.In another example, each resource within the failure detection resourcesused to transmit the BFD reference signals may be configured with aCORESET pool index value. In some cases, if a resource is not configuredwith a CORESET pool index value, it is assumed to be associated withCORESET pool index value zero. In some cases, a BFD reference signalresource may be configured with both values of CORESET pool index, inwhich case the associated reference signal may be considered for bothTRPs. In some cases, when failure detection resources are notconfigured, reference signal sets indicated by the active TCI states ofCORESETs configured with CORESET pool index zero or one determines thefirst and second sets of resources, respectively. In some cases, a beamfailure for a value of CORESET pool index may be declared when radiolink quality is worse than the configured threshold value (e.g.,Q_(out)) for all the reference signals in the BFD resources that areassociated with that CORESET pool index value.

At communication 380, in response to the detecting the BFD at the Scell376, the UE 372 transmits an SR indication to the Pcell 374 (over an FR1frequency carrier of the Pcell 374) via a scheduling request (SR). Insome aspects, the UE 372 may transmit the SR over a PUCCH resource, forexample, using a PUCCH format 0 or a PUCCH format 1. The SR indicationmay request the Pcell 374 to provide the UE 372 with PUSCH resources,which may be used by the UE 372 to transmitting a BFRQ for the Scell376. In other words, the UE 372 may determine to initiate a BFR for theScell 376 by transmitting the SR indication.

In some aspects, the UE 372 may initiate a BFR for the Scell 376 basedon a beam group BFD parameter or a cell-level BFD parameter. The SRindication may indicate that the UE 344 is requesting uplink resources,which the SR indication may be transmitted using a PUCCH resource. Insome cases, two PUCCH resources can be configured for requesting BFR forthe Scell 376 (e.g., indicated by schedulingRequestID-BFR-Scell) by twocorresponding scheduling request IDs. The PUCCH resources or schedulingrequest IDs may be associated with the values of CORESET pool index. IfBFD is declared for a value of CORESET pool index in Scell 376, in somecases, the PUCCH resource/scheduling request ID that corresponds toanother value of CORESET pool index may be used for LRR transmission.Such a selection of resources provides that if the beams of Scell 376and a PUCCH-cell are the same, and if all beams for one TRP become weak,the SR indication (the BFR request for the Scell 376) can be transmittedusing a beam corresponding to the other TRP. Such a rule may be applied,for example, when the CC with PUCCH-BFR is in the same band as the Scell376.

In other cases, the PUCCH resource/scheduling request ID thatcorresponds to the same value of CORESET pool index is used for the SRindication transmission. Such a selection may provide that the SRindication is transmitted to the same TRP for non-ideal backhaulscenario. Such a rule may be followed, for example, when separatefeedback is configured for different cells(ACKNACKFeedbackMode=SeparateFeedback). In other cases, the PUCCHresource/scheduling request ID that corresponds to CORESET pool index=0is used for SR indication (the BFR request for the Scell 376)transmission. Such a rule can be followed, for example, when the CC withPUCCH-BFR is in a different band than the Scell 376. In still othercases, multiple PUCCH resources/scheduling request IDs may be used totransmit the SR indication irrespective of the CORESET pool index forwhich BFD is declared. This means that multiple instances of the SRindication transmission are provided across the multiple PUCCH resources(and transmitted to both TRPs).

At communication 382, the Pcell 374 may provide an uplink grant to theUE 372. Such an uplink grant may be a normal uplink grant withC-RNTI/MCS-C-RNTI that can serve as response to the SR indication (theBFR request for the Scell 376), which the UE 372 may use to transmit aPUSCH in which a BFRQ MAC-CE can be transmitted. It is noted that insome cases the UE 344 may have an existing uplink grant, in which casesthe LRR and associated uplink grant operations may be skipped.

At communication 384, the UE 372 may transmit a beam failure reportindicating a BFD at the Scell 376 in a BFR MAC-CE (a BFRQ). Examples ofthe BFR MAC-CE are discussed further below. The BFR MAC-CE istransmitted using the resources provided in the uplink grant, and can besent on any cell, including failed SCell 376. In some cases, the UE 372may indicate the CORESET pool index value in the Scell MAC-CE for thecorresponding Scell 376. In general, the UE 372 may indicate a beamfailure and a desired or candidate beam for recovery. Such an indicationmay be provided, in some cases, in accordance with the examplesdiscussed further below.

At communication 386, the Pcell 374 may provide a BFR configuration tothe UE 372 for performing a BFR for the Scell 376. The FR configurationmay indicate a new CORESET with a TCI State Activation for Scell 376 ina PUCCH TCI update. In some aspects, the BFR configuration may be basedon a beam group BFD parameter or a cell-level BFD parameter. In somecases, the response may be an uplink grant to schedule a newtransmission (e.g., with a toggled new data indicator (NDI)) for thesame HARQ process as the PUSCH carrying the BFR MAC-CE. In some cases,if a new beam corresponding to a value of CORESET pool index in theScell 346 is reported in the BFR MAC-CE, after 28 symbols from the endof the BFR response (end of PDCCH), the UE 344 may use a QCL assumptionthat only the CORESETs with the same value of CORESET pool index arereset to the new beam (e.g., q_(new)) in the Scell 346. Assuming thatPUCCH resources are also associated with a value of CORESET pool index,spatial relation for only those PUCCH resources that are associated withthe same value of CORESET pool index are reset to the new beam in theScell 346 when the Scell 346 is a PUCCH-Scell. If PUCCH resources arenot associated with a value of CORESET pool index, and if BFR MAC-CEindicates BFD and candidate beams for both values of CORESET pool index(e.g., two q_(new) in the Scell 346), PUCCH beams are reset to thecandidate beam corresponding to CORESET pool index=0 (when Scell isPUCCH-Scell).

Thus, in some cases the UE 344 may reset the beams for one or more PUCCHresources associated with the same value as the CORESET pool index valueof the identified candidate beam, when the secondary cell is configuredfor uplink control information transmissions. Further, in some cases,the UE 344 may reset the beams for one or more PUCCH resources inresponse to the CORESET pool index value of the identified candidatebeam having a first value (e.g., CORESET pool index=0), and refrain fromresetting the beams for the one or more PUCCH resources in response tothe CORESET pool index value of the identified candidate beam having asecond value (e.g., CORESET pool index=1), when the secondary cell isconfigured for uplink control information transmissions.

At step 388, the Scell 376 may perform DL channel recovery and the DLchannel recovered.

At communication 390, the Scell 376 may provide the UE 372 with a PDCCHDCI (e.g., transmitted via a FR2 frequency of the Scell 376. The PDCCHDCI may be transmitted based on a C-RNTI of the UE 372. The PDCCH DCImay indicate a resource for the UE 372 to transmit a RACH request (e.g.,a RACH preamble or MSG1).

At communication 392, upon receiving the PDCCH DCI, the UE 372 maytransmit a RACH request using the resource indicated by the PDCCH DCIreceived at communication 390.

At communication 394, upon receiving the RACH request, the Scell 376 mayrespond with MSG2. In some aspects, the MSG2 may indicate a schedulinggrant for the UE 372 to transmit a UL communication. At which point,Scell UL channel is recovered at step 396.

The BFD and BFR procedures discussed herein can be executed on UEs andBSs implemented in the networks illustrated in FIG. 1 and FIG. 2A.Consequently, FIG. 4 illustrates an example UE 400 and FIG. 5illustrates an example BS 500 according to some embodiments as discussedherein.

FIG. 4 is a block diagram of an exemplary UE 400 according to someaspects of the present disclosure. The UE 400 may be a UE 115, 205, 310,344, 372 as discussed above in FIGS. 1, 2A, 3A, 3B, and 3C. As shown,the UE 400 may include a processor 402, a memory 404, communicationsmodule 408, a BFD/BFR module 409, a transceiver 410 including a modemsubsystem 412 and a radio frequency (RF) unit 414, and one or moreantennas 416. These elements may be in direct or indirect communicationwith each other, for example via one or more buses.

The processor 402 may include a central processing unit (CPU), a digitalsignal processor (DSP), an application specific integrated circuit(ASIC), a controller, a field programmable gate array (FPGA) device,another hardware device, a firmware device, or any combination thereofconfigured to perform the operations described herein. The processor 402may also be implemented as a combination of computing devices, e.g., acombination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration.

The memory 404 may include a cache memory (e.g., a cache memory of theprocessor 402), random access memory (RAM), magnetoresistive RAM (MRAM),read-only memory (ROM), programmable read-only memory (PROM), erasableprogrammable read only memory (EPROM), electrically erasableprogrammable read only memory (EEPROM), flash memory, solid state memorydevice, hard disk drives, other forms of volatile and non-volatilememory, or a combination of different types of memory. In an aspect, thememory 404 includes a non-transitory computer-readable medium. Thememory 404 may store, or have recorded thereon, instructions 406. Theinstructions 406 may include instructions that, when executed by theprocessor 402, cause the processor 402 to perform the operationsdescribed herein with reference to the UEs 115 in connection withaspects of the present disclosure, for example, aspects of FIGS. 2A-2B,3A-3C, 6-8, 9A-9D, 10, and 11 . Instructions 406 may also be referred toas program code. The program code may be for causing a wirelesscommunication device to perform these operations, for example by causingone or more processors (such as processor 402) to control or command thewireless communication device to do so. The terms “instructions” and“code” should be interpreted broadly to include any type ofcomputer-readable statement(s). For example, the terms “instructions”and “code” may refer to one or more programs, routines, sub-routines,functions, procedures, etc. “Instructions” and “code” may include asingle computer-readable statement or many computer-readable statements.

Communications module 408, through transceiver 410, may establish aconnection with at least a first beam group (e.g. TRP) using a first setof one or more beams and a second beam group (e.g. TRP) using a secondset of one or more beams, where each of the first beam group and thesecond beam group are associated with a secondary cell of UE 400. Ingeneral, communications module 408, through transceiver 410, mayestablish a connection with multiple beam groups (e.g. mTRPs).

Communications module 408 may, as described herein, be implemented torealize one or more potential advantages. One implementation may allowthe UE 408 to provide BFD indications and candidate beams for particularTRPs in a serving cell that uses multiple TRPs, which may enhance theoverall channel quality of the network performance and allow forindication of failed beams of particular TRPs before an overall failureof the serving cell. Further, such implementations may allow UE 408 toincrease communications reliability, throughput, and user experience,while reducing overall power consumption, among other advantages.

Communications module 408 may be implemented in hardware, code (e.g.,software or firmware) executed by a processor, or any combinationthereof. If implemented in code executed by a processor, the functionsof the communications module 408, or its sub-components may be executedby a general-purpose processor, a DSP, an application-specificintegrated circuit (ASIC), a FPGA or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described in thepresent disclosure. In particular, communications module 408 may beimplemented on processor 402.

The BFD/BFR module 409 may be implemented via hardware, software, orcombinations thereof. For example, the BFD/BFR module 409 may beimplemented as a processor, circuit, and/or instructions 406 stored inthe memory 404 and executed by the processor 402. In some instances, theBFD/BFR module 409 can be integrated within the modem subsystem 412 andcommunications module 408. For example, the BFD/BFR module 409 can beimplemented by a combination of software components (e.g., executed by aDSP or a general processor) and hardware components (e.g., logic gatesand circuitry) within the modem subsystem 412.

The BFD/BFR module 409 may be used for various aspects of the presentdisclosure, for example, aspects of aspects of FIGS. 2A-2B, 3A-3C, 6-8,9A-9D, 10, and 11 . The BFD/BFR module 409 can be configured to performbeam failure detection (BFD) and beam failure recovery (BFR) techniquesbased on one or more beam group parameter(s) and/or one or morecell-level parameter(s) as described herein. In particular, BFD/BFRmodule 409 can determine a beam failure configuration for a servingcell. The beam failure configuration can include at least one of a beamfailure parameter of a beam group or a beam failure parameter of a cell.The BFD/BFR module 409 can also perform a beam failure detection in theserving cell based at least in part on the beam failure configuration.In this regard, the BFD/BFR module 409, along with communications module408 and/or transceiver 410, may transmit a beam failure recovery requestmessage that indicates the failed beam and candidate replacement beams.Additional aspects of operation of the BFD/BFR module 409 is furtherdiscussed below.

As discussed above, a UE operating in a serving cell(PCell/SCell/SpCell) may operate with beam group specific beam failureparameters, cell-level beam failure parameters, or combinations of beamgroup specific and cell-level BFR beam failure parameters according to abeam failure configuration based on aspects of the present disclosure.For example, a UE operating in a serving cell can be configured toperform beam group specific beam failure detection (BFD), cell levelBFD, beam group specific beam failure recovery (BFR), cell BFR, radiolink monitoring (RLM), radio link failure (RLF) recovery, and/orcombination thereof. Accordingly, in some aspects the BFD/BFR module409, in combination with other components and features of the UE 400,may facilitate the performance of group specific BFD, cell level BFD,beam group specific BFR, cell BFR, RLM, and/or RLF recovery inaccordance with the present disclosure. In this regard, the BFD/BFRmodule 409 may determine which type(s) of BFD, BFR, and/or RLM/RLFshould be performed and associated parameters. The BFD/BFR module 409may cause the UE to initiate performance of one or more of the groupspecific BFD, cell level BFD, beam group specific BFR, cell BFR, RLM,and/or RLF recovery based on the determination.

As shown, the transceiver 410 may include the modem subsystem 412 andthe RF unit 414. The transceiver 410 can be configured to communicatebi-directionally with other devices, such as the BSs 105. The modemsubsystem 412 may be configured to modulate and/or encode the data fromthe memory 404 and/or the communication module 408 according to amodulation and coding scheme (MCS), e.g., a low-density parity check(LDPC) coding scheme, a turbo coding scheme, a convolutional codingscheme, a digital beamforming scheme, etc. The RF unit 414 may beconfigured to process (e.g., perform analog to digital conversion ordigital to analog conversion, etc.) modulated/encoded data (e.g., PUCCHcontrol information, PRACH signals, PUSCH data, SR indication, BFRrequest, MSG1, BFR MAC-CE) from the modem subsystem 412 (on outboundtransmissions) or of transmissions originating from another source suchas a UE 115 or a BS 105. The RF unit 414 may be further configured toperform analog beamforming in conjunction with the digital beamforming.Although shown as integrated together in transceiver 410, the modemsubsystem 412 and the RF unit 414 may be separate devices that arecoupled together at the UE 115 to enable the UE 115 to communicate withother devices.

The RF unit 414 may provide the modulated and/or processed data, e.g.data packets (or, more generally, data messages that may contain one ormore data packets and other information), to the antennas 416 fortransmission to one or more other devices. The antennas 416 may furtherreceive data messages transmitted from other devices. The antennas 416may provide the received data messages for processing and/ordemodulation at the transceiver 410. The transceiver 410 may provide thedemodulated and decoded data (e.g., SSBs, RMSI, MIB, SIB, PRACHconfiguration, PDCCH, PDSCH, MSG2, UL grants, RRC configurations, BFDconfigurations, BFR configurations) to the communication module 408 forprocessing. The antennas 416 may include multiple antennas of similar ordifferent designs in order to sustain multiple transmission links. TheRF unit 414 may configure the antennas 416.

In an aspect, the UE 400 can include multiple transceivers 410implementing different RATs (e.g., NR and LTE). In an aspect, the UE 400can include a single transceiver 410 implementing multiple RATs (e.g.,NR and LTE). In an aspect, the transceiver 410 can include variouscomponents, where different combinations of components can implementdifferent RATs.

FIG. 5 is a block diagram of an exemplary BS 500 according to someaspects of the present disclosure. The BS 500 may be a BS 105 in thenetwork 100 as discussed above in FIG. 1 , a Pcell/Scell 210, 305, 342,346, 374, 376 as discussed above in FIGS. 2A, 3A, 3B, and 3C, and/or aTRP 215 as discussed above in FIG. 2A. As shown, the BS 500 may includea processor 502, a memory 504, a communication module 508, a BFR module509, a transceiver 510 including a modem subsystem 512 and a RF unit514, and one or more antennas 516. These elements may be in direct orindirect communication with each other, for example via one or morebuses, and may, in some cases, be operated on a single processor 502.

The processor 502 may have various features as a specific-typeprocessor. For example, these may include a CPU, a DSP, an ASIC, acontroller, a FPGA device, another hardware device, a firmware device,or any combination thereof configured to perform the operationsdescribed herein. The processor 502 may also be implemented as acombination of computing devices, e.g., a combination of a DSP and amicroprocessor, a plurality of microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration.

The memory 504 may include a cache memory (e.g., a cache memory of theprocessor 502), RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, asolid-state memory device, one or more hard disk drives, memristor-basedarrays, other forms of volatile and non-volatile memory, or acombination of different types of memory. In some aspects, the memory504 may include a non-transitory computer-readable medium. The memory504 may store instructions 506. The instructions 506 may includeinstructions that, when executed by the processor 502, cause theprocessor 502 to perform operations described herein, for example,aspects of FIGS. 2, 3A-3B, and 6-10. Instructions 506 may also bereferred to as code, which may be interpreted broadly to include anytype of computer-readable statement(s) as discussed above with respectto FIG. 4 .

Communications module 508 may establish communications with a UE such asUE 400 via a serving cell (e.g., primary cell and/or a secondary cell),where communications via the serving cell use multiple beams. Forexample, a first transmission-reception point of the serving cell mayuse a first set of one or more beams and a second transmission-receptionpoint of the serving cell may use a second set of one or more beams,configure a first uplink resource associated with the firsttransmission-reception point and a second uplink resource associatedwith the second transmission-reception point for transmission of arecovery request message that indicates a beam failure of the servingcell at the UE through BFR module 509, receive the recovery requestmessage from the UE, and determine in BFR module 509, based on therecovery request message, that the UE has declared a beam failure.

Communications module 508, or its sub-components, may be implemented inhardware, code (e.g., software or firmware) executed by a processor, orany combination thereof. If implemented in code executed by a processor,the functions of communications module 508, or its sub-components may beexecuted by a general-purpose processor, a DSP, an application-specificintegrated circuit (ASIC), a FPGA or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described in thepresent disclosure.

BFR module 509 is coupled with communications module 508 and/ortransceiver 510 to receive messages from the UE declaring a beamfailure. In some instances, the BFR module 509 is configured to transmitone or more RRC messages or other communications to the UE that providean indication of the available beam failure detection and/or recoverytypes (e.g., beam group or TRP-specific, cell level, BFR, RLF, etc.)available for use by the UE in the serving cell, including in someinstances an explicit or implicit indication of associated parameters(e.g., resource(s), reference signals (BFD RSs), etc.). In someinstances, the BFR module 509 is configured to transmit an indication ofone or more threshold(s) for the UE to utilize in determining whattype(s) of BFD, BFR, and/or RLM/RLF to perform in the serving cell undervarious situations. In some instances, one or more of the thresholds isdynamically configured by the BFR module 509. In some instances, thethreshold(s) may be defined by a standard specification or otherwisepredefined. Various aspects of the present disclosure, for example,aspects of aspects of FIGS. 2A-2B, 3A-3C, 6-8, 9A-9D, and 10-12 can beperformed by BFR module 509.

As shown, the transceiver 510 may include the modem subsystem 512 andthe RF unit 514. The transceiver 510 can be configured to communicatebi-directionally with other devices, such as the UEs 115 and/or 400and/or another core network element. The modem subsystem 512 may beconfigured to modulate and/or encode data according to a MCS, e.g., aLDPC coding scheme, a turbo coding scheme, a convolutional codingscheme, a digital beamforming scheme, etc. The RF unit 514 may beconfigured to process (e.g., perform analog to digital conversion ordigital to analog conversion, etc.) modulated/encoded data (e.g., SSBs,RMSI, MIB, SIB, PRACH configuration PDCCH, PDSCH, MSG2, UL grants, RRCconfigurations, BFD configurations, BFR configurations, RLMconfigurations, RLF configurations) from the modem subsystem 512 (onoutbound transmissions) or of transmissions originating from anothersource such as a UE 115, the UE 315, and/or UE 400. The RF unit 514 maybe further configured to perform analog beamforming in conjunction withthe digital beamforming. Although shown as integrated together intransceiver 510, the modem subsystem 512 and/or the RF unit 514 may beseparate devices that are coupled together at the BS 105 to enable theBS 105 to communicate with other devices.

The RF unit 514 may provide the modulated and/or processed data, e.g.data packets (or, more generally, data messages that may contain one ormore data packets and other information), to the antennas 516 fortransmission to one or more other devices. This may include, forexample, transmission of information to complete attachment to a networkand communication with a camped UE 115 or 400 according to some aspectsof the present disclosure. The antennas 516 may further receive datamessages transmitted from other devices and provide the received datamessages for processing and/or demodulation at the transceiver 510. Thetransceiver 510 may provide the demodulated and decoded data (e.g.,PUCCH control information, PRACH signals, PUSCH data, SR indication, BFRrequest, MSG1, BFR MAC-CE) to the communication module 508 forprocessing. The antennas 516 may include multiple antennas of similar ordifferent designs in order to sustain multiple transmission links.

In an aspect, the BS 500 can include multiple transceivers 510implementing different RATs (e.g., NR and LTE). In an aspect, the BS 500can include a single transceiver 510 implementing multiple RATs (e.g.,NR and LTE). In an aspect, the transceiver 510 can include variouscomponents, where different combinations of components can implementdifferent RATs.

FIG. 6 is a flow diagram illustrating a communication method 600according to some aspects of the present disclosure. Aspects of themethod 600 can be executed by a computing device (e.g., a processor,processing circuit, and/or other suitable component) of a wirelesscommunication device or other suitable means for performing the steps.For example, a wireless communication device, such as a UE 115 or the UE400, may utilize one or more components, such as the processor 402, thememory 404, the communications module 408, the BFD/BFR module 409, thetransceiver 410, and/or the one or more antennas 416, to execute aspectsof the method 600. Further, the method 600 may employ similar mechanismsas described in FIGS. 2A-3C, as well as aspects of FIGS. 6-8, 9A-9D, and10-12 . In some instances, aspects of the method 600 may be implementedbetween a UE 115 and a BS 105 of a serving cell, which may includemultiple beam groups. As illustrated, the method 600 includes a numberof enumerated steps, but the method 600 may include additional aspectsbefore, after, and in between the enumerated steps. In some aspects, oneor more of the enumerated steps may be omitted or performed in adifferent order.

At block 602, the UE receives from a BS a message or communicationincluding a beam failure configuration for a serving cell. In someinstances, the UE determines the beam failure configuration for theserving cell from or based on the message or communication. The servingcell may be a primary cell (PCell) and/or a secondary cell (SCell). Insome instances, the UE determines the beam failure configuration for theserving cell based on an RRC message or other communication from a basestation. In this regard, the RRC message or other communication from theBS may provide an indication of the available beam failure detectionand/or recovery types (e.g., beam group or TRP-specific, cell level,BFR, RLF, etc.) available for use by the UE in the serving cell,including in some instances an explicit or implicit indication ofassociated parameters (e.g., resource(s), reference signals, etc.).

The beam failure configuration can include at least one of a beamfailure parameter of a beam group (e.g., TRP, beam direction, componentcarrier, etc.) or a beam failure parameter of a cell (e.g., servingcell, primary cell, secondary cell). In some instances, beam groupspecific BFD and/or beam group specific BFR may be simultaneouslyconfigured on the same serving cell with cell BFD and/or cell BFR.Accordingly, in some instances BFD in a serving cell can be configuredwith beam group specific BFD and cell BFD. Similarly, in some instancesBFR in a serving cell can be configured with beam group specific BFR andcell BFR. In some instances, BFD in a serving cell can be configuredwith only beam group specific BFD or only cell BFD, while BFR in theserving cell can be configured with beam group specific BFR and cellBFR. In some instances, BFD in a serving cell can be configured withbeam group specific BFD and cell BFD, while BFR in the serving cell canbe configured only with beam group specific BFR or only cell BFR. Insome instances, BFD in a serving cell can be configured with only beamgroup specific BFD or only cell BFD, while BFR in the serving cell canbe configured with only beam group specific BFR or only cell BFR. Whenboth beam group specific and cell configurations are available for usein a serving cell for BFD and/or BFR, the UE may determine whether touse the beam group specific, cell, or both configurations in performingthe BFD and/or the BFR. In this regard, the beam failure configurationmay be determined with consideration of various configuration optionsand/or associated rules as further discussed below.

At block 604, the UE performs beam failure detection based at least inpart on the beam failure configuration determined at 602. In someinstances, the UE detects a beam failure at block 604. The beam failuremay be associated with one or more beams of a beam group of the servingcell. In some instances, the beam group is associated with one or moreTRPs of the serving cell. In response to detecting a beam failure at604, the UE may initiate a recovery (e.g., BFR and/or RLF recovery). Insome cases, the recovery is performed based at least in part on the beamfailure configuration determined at 602.

In some aspects, the UE determines, at 602, that the beam failureconfiguration for the serving cell includes the beam failure parameterof the beam group and does not include the beam failure parameter of thecell. Accordingly, the UE may perform the beam failure detection, at604, based on the beam failure parameter of the beam group. In thisregard, the UE may detect the beam failure based on the beam failureparameter of the beam group. In some instances, the beam failureparameter of the beam group includes one or more BFD parameters (e.g.,information regarding BFD RSs) associated with the beam group. In thisregard, the beam group may be associated with a TRP of the serving cell.For example, the beam failure parameter of the beam group may include atleast one of a transmission-reception point (TRP)-specific beam failuredetection (BFD) parameter or a TRP-specific beam failure recovery (BFR)parameter. In some instances, the UE determines, at block 602, that thebeam failure configuration for the serving cell includes a plurality oftransmission-reception point (TRP)-specific beam failure parametersassociated with a plurality of TRPs and the UE performs the beam failuredetection, at 604, by independently performing beam failure detectionfor each of the plurality of TRPs.

In some aspects, the UE determines, at 602, that the beam failureconfiguration for the serving cell includes the beam failure parameterof the cell (e.g., serving cell, primary cell, secondary cell) and doesnot include the beam failure parameter of the beam group. In thisregard, the UE may determine, at 602, that the beam failure parameter ofthe cell comprises at least one of a cell-level beam failure detection(BFD) parameter or a cell-level beam failure recovery (BFR) parameter.Accordingly, the UE may perform the beam failure detection, at 604,based on the beam failure parameter of the cell. In this regard, the UEmay detect the beam failure based on the beam failure parameter of thecell.

In some aspects, the UE determines, at 602, that the beam failureconfiguration for the serving cell includes a beam group-specific beamfailure detection parameter and a cell-level beam failure detectionparameter. In some instances, the UE determines that the beam failureparameter of the beam group includes a beam group-specific beam failuredetection (BFD) parameter and that the beam failure parameter of thecell includes a cell-level BFD parameter. In some aspects, the UEperforms the beam failure detection, at 604, by performing a first beamfailure detection (BFD) based on the beam group-specific beam failuredetection parameter and performing a second BFD based on the cell-levelbeam failure detection parameter. In some cases, the UE performs thefirst BFD based on the beam group-specific beam failure detectionparameter by monitoring for at least one transmission-reception point(TRP)-specific BFD reference signal (RS). Similarly, in some cases theUE performs the second BFD based on the cell-level beam failuredetection parameter by monitoring for at least one cell-level BFD RS. Insome instances, the at least one TRP-specific BFD reference signal (RS)is independent of the at least one cell-level BFD RS. In some instances,the at least one TRP-specific BFD reference signal (RS) is based on theat least one cell-level BFD RS. For example, in some instances eachTRP-specific BFD RS is within the set of available cell-level BFD RSs.That is, the TRP-specific BFD RSs for a cell can be a subset of orinclude all of the cell-level BFD RSs for the serving cell.

In some aspects, the UE further determines, at 602, that the beamfailure configuration for the serving cell includes a beamgroup-specific beam failure recovery (BFR) parameter and does notinclude a cell-level beam failure recovery (BFR) parameter. Accordingly,in some instances, the UE determines the beam failure configurationincludes a beam group-specific beam failure detection (BFD) parameter, acell-level BFD parameter, and a beam group-specific BFR parameter, butdoes not include a cell-level BFR parameter. In some cases, the UEperforms a BFR, in response to the detecting the beam failure at 604,based on the beam group-specific BFR parameter.

In some aspects, the UE further determines, at 602, that the beamfailure configuration for the serving cell includes a cell-level beamfailure recovery (BFR) parameter and does not include a beamgroup-specific beam failure recovery (BFR) parameter. Accordingly, insome instances, the UE determines the beam failure configurationincludes a beam group-specific beam failure detection (BFD) parameter, acell-level BFD parameter, and a cell-level BFR parameter, but does notinclude a beam group-specific BFR parameter. In some cases, the UEperforms a BFR, in response to the detecting the beam failure at 604, aBFR based on the cell-level BFR parameter.

In some aspects, the UE determines, at 602, that the beam failureparameter of the beam group includes a transmission-reception point(TRP)-specific beam failure detection (BFD) parameter and a TRP-specificbeam failure recovery (BFR) parameter. Accordingly, in some instances,the UE determines the beam failure configuration includes a TRP-specificBFD parameter, a TRP-specific BFR parameter, and at least one of acell-level BFD parameter and/or a cell-level BFR parameter. The UE mayperform the beam failure detection, at 604, based on the TRP-specificBFD parameter. In some instances, the TRP-specific BFD parameterincludes one or more BFD parameters (e.g., information regardingTRP-specific BFD RSs) associated with the TRP. Further, the UE mayperform, in response to the BFD based on the TRP-specific BFD parameterat 604 indicating the beam failure, a BFR procedure based on theTRP-specific BFR parameter.

In some aspects, the UE determines, at 602, that the beam group-specificbeam failure detection parameter includes a transmission-reception point(TRP)-specific beam failure detection (BFD) parameter and the cell-levelbeam failure detection parameter includes a cell-level beam failurerecovery (BFR) parameter. Accordingly, in some cases the UE performs thebeam failure detection, at 604, based on the TRP-specific BFD parameterand, in response to the BFD indicating a beam failure, performs a BFRbased on the cell-level BFR parameter.

In some aspects, the UE determines, at 602, that the beam group-specificbeam failure detection parameter includes a transmission-reception point(TRP)-specific beam failure detection (BFD) parameter and a TRP-specificbeam failure recovery (BFR) parameter and that the cell-level beamfailure detection parameter includes a cell-level BFD parameter and acell-level BFR parameter. Accordingly, in some cases the UE performs thebeam failure detection, at 604, by performing a first BFD based on theTRP-specific BFD parameter and performing a second BFD based on thecell-level BFD parameter. In some instances, the UE performs, inresponse to the first BFD (based on the TRP-specific BFD parameter)indicating a beam failure, a first BFR based on the TRP-specific BFRparameter. In some instances, the UE performs, in response to the secondBFD (based on the cell-level BFD parameter) indicating a beam failure, asecond BFR based on the cell-level BFR parameter.

In some aspects, the UE determines, at 602, that the beam failureconfiguration for the serving cell includes a plurality oftransmission-reception point (TRP)-specific beam failure parametersassociated with a plurality of TRPs. In some instances, the UE performsthe beam failure detection, at 604, by performing a beam failuredetection (BFD) for each of the plurality of TRPs. In some case, the UEperforms a beam failure recovery (BFR) based on a number of the BFDsindicating a beam failure. For example, in some instances if the numberof BFDs indicating a beam failure is less than (or equal to) a threshold(or the threshold is otherwise met), then the UE may perform aTRP-specific BFR. In some instances, if one or more BFDs indicate a beamfailure, but at least X other TRPs are working (e.g., do not have beamfailure detected or have an ongoing BFR), then the UE may initiate aTRP-specific BFR for the one or more BFDs where beam failure wasdetected. If the number of BFDs indicating a beam failure is greaterthan (or equal to) a threshold Y (or the threshold is otherwise met),then the UE may perform a cell-level BFR. In some instances, the UEimmediately triggers the performing of the cell-level BFR in response tothe number of beam failures being greater than (or equal to) thethreshold (or otherwise meeting the threshold). In some cases, thethreshold Y is all TRPs in a serving cell. In some cases, the thresholdY is a number less than all of the TRPs in a serving cell or apercentage of the TRPs in the serving cell. In some instances, theperformance of the BFR by the UE includes disallowing a cell-level BFRwhen a threshold number of working TRPs is exceeded. That is, if thebeam failure detection, at 604, indicates a threshold number Z of TRPs(e.g., 1 or more) associated with a with the serving cell (or acomponent carrier or other beam group of the serving cell) are working(e.g., do not have beam failure detected or have an ongoing BFR, orbecome working with successful TRP-specific BFR), then the UE willrefrain from initiating a cell-level BFR. In some instances, the method600 includes the UE receiving, from a base station of the serving cell,an indication of at least one threshold value for determining whether toperform a TRP-specific BFR or a cell-level BFR. The threshold(s) may beassociated with determining when to perform (or refrain from performing)the TRP-specific BFR and/or the cell-level BFR. In some instances, anindication of the threshold(s) (e.g., X, Y, and Z, or otherwise) isincluded in an RRC message or other communication from a base station.In this regard, the threshold(s) may be included in the RRC message (orother communication) from the BS that provides an indication of theavailable beam failure detection and/or recovery types (e.g., beam groupor TRP-specific, cell level, BFR, RLF, etc.) available for use by the UEin the serving cell. In some instances, the threshold(s) may be definedby a standard specification or otherwise predefined.

In some aspects, the UE performs, in response to detection of a beamfailure at 604, a cell-level beam failure recovery (BFR) and terminatesany active TRP-specific BFRs. In this regard, the UE may terminate anyactive TRP-specific and/or beam group-specific BFRs upon the initiationof a cell-level BFR. Further, in some instances, the UE may refrain frominitiating any TRP-specific and/or beam group-specific BFRs whileperforming the cell-level BFR.

In some aspects, the UE determines, at 602, that the beam group-specificbeam failure detection parameter includes a plurality oftransmission-reception point (TRP)-specific beam failure parametersassociated with a plurality of TRPs and the cell-level beam failuredetection parameter includes a radio-link failure (RLF) parameter.Accordingly, in some cases the UE performs the beam failure detection,at 604, for each of the plurality of TRPs based on the TRP-specific BFDparameters. Further, in some instances, the UE performs a recovery basedon a number of the BFDs indicating a beam failure. For example, in someinstances if the number of BFDs indicating a beam failure is less than(or equal to) a threshold (or the threshold is otherwise met), then theUE may perform a TRP-specific BFR. In some instances, if one or moreBFDs indicate a beam failure, but at least X other TRPs are working(e.g., do not have beam failure detected or have an ongoing BFR), thenthe UE may initiate a TRP-specific BFR for the one or more BFDs wherebeam failure was detected. If the number of BFDs indicating a beamfailure is greater than (or equal to) a threshold Y (or the threshold isotherwise met), then the UE may perform a RLF recovery. In someinstances, the UE immediately triggers the performing of the RLFrecovery in response to the number of beam failures being greater than(or equal to) the threshold (or otherwise meeting the threshold). Insome cases, the threshold Y is all TRPs in a serving cell. In somecases, the threshold Y is a number less than all of the TRPs in aserving cell or a percentage of the TRPs in the serving cell. In someinstances, the performance of the recovery by the UE includes notallowing a RLF recovery when a threshold number of working TRPs isexceeded. That is, if the beam failure detection, at 604, indicates athreshold number Z of TRPs (e.g., 1 or more) associated with a with theserving cell (or a component carrier or other beam group of the servingcell) are working (e.g., do not have beam failure detected or have anongoing BFR, or become working with successful TRP-specific BFR), thenthe UE will refrain from initiating a RLF recovery. In some instances,the method 600 includes the UE receiving, from a base station of theserving cell, an indication of at least one threshold value fordetermining whether to perform a TRP-specific BFR or a RLF recovery. Thethreshold(s) may be associated with determining when to perform (orrefrain from performing) the TRP-specific BFR and/or the RLF recovery.In some instances, an indication of the threshold(s) (e.g., X, Y, and Z,or otherwise) is included in an RRC message or other communication froma base station. In this regard, the threshold(s) may be included in theRRC message (or other communication) from the BS that provides anindication of the available beam failure detection and/or recovery types(e.g., beam group or TRP-specific, cell level, BFR, RLF, etc.) availablefor use by the UE in the serving cell. In some instances, thethreshold(s) may be defined by a standard specification or otherwisepredefined.

In some aspects, the UE performs, in response to detection of a beamfailure at 604, a RLF recovery and terminates any active TRP-specificBFRs in the serving cell (e.g., SpCell). In this regard, the UE mayterminate any active TRP-specific and/or beam group-specific BFRs uponthe initiation of a RLF recovery. Further, in some instances, the UE mayrefrain from initiating any TRP-specific and/or beam group-specific BFRswhile performing the RLF recovery.

In some aspects, the UE performs the beam failure detection, at 604, byperforming a beam failure detection (BFD) based on the beam groupspecific beam failure detection parameter and performing a radio linkmonitoring (RLM) based on the cell-level beam failure detectionparameter. In some instances, the UE performs the BFD based on the beamgroup-specific beam failure detection parameter by monitoring for atleast one transmission-reception point (TRP)-specific BFD referencesignal (RS). In some instances, the UE performs the RLM based on thecell-level beam failure detection parameter by monitoring for at leastone RLM RS. In some instances, the at least one TRP-specific BFDreference signal (RS) is independent of the at least one RLM RS. In somecases, the at least one TRP-specific BFD RS is based on the at least oneRLM RS. For example, in some instances each TRP-specific BFD RS iswithin the set of available RLM RSs. That is, the TRP-specific BFD RSsfor a cell can be a subset of or include all of the RLM RSs for theserving cell.

In some aspects, the method 600 includes the UE triggering a radio linkfailure (RLF) recovery. In some instances, the UE performs, followingthe triggering of the RLF recovery, a plurality oftransmission-reception point (TRP)-specific BFD procedures. In somecases, the UE may adjust a timer associated with the RLF procedure(e.g., T310 timer) based on a consecutive number of the TRP-specificBFDs indicating a beam failure. The adjusting the timer can includeincreasing or decreasing the timer by at least one of a predeterminedamount of time or a percentage of a duration of the timer. For example,in some instances, if the consecutive number of the TRP-specific BFDsindicating a beam failure exceeds a threshold, then the UE can adjustthe timer (e.g., reduce or speed up the timer for x ms or a certainpercentage (e.g., 10%, 20%, 25%, 50%, or otherwise) of the total timerexpiration duration). In some instances, the UE determines whether toadjust the timer based on the consecutive number of the TRP-specific BFDindicating the beam failure at a single TRP. That is, the UE determineswhether to adjust the timer based on how many times in a row the sameTRP causes the TRP-specific BFD to indicate a beam failure. In someinstances, the UE determines whether to adjust the timer based on theconsecutive number of the TRP-specific BFDs indicating the beam failureat a plurality of TRPs. That is, the UE determines whether to adjust thetimer based on how many times in a row the any TRP (or any TRP in agroup of TRPs) indicates a beam failure as a result of the TRP-specificBFD. In some instances, the UE determines the amount to adjust the timerbased on the number of TRPs indicating a beam failure. For example, insome cases the reduction in the timer is based on the number of TRPswith beam failure (e.g., 1 TRP=x ms or y %; 2 TRPs=2x ms or 2y %; 3TRP=3x ms or 3y %; 4 TRPs=4x ms or 4y %). Accordingly, in some instancesthe UE adjusts the timer based on a number of TRPs associated with theTRP-specific BFDs indicating the beam failure.

FIG. 7 illustrates a recovery 700 that includes detection of a beamfailure in step 702 and a recovery in step 704. As indicated in FIG. 7 ,detection of a beam failure in step 702 can include either a beamfailure detection (BFD) or a radio link monitoring (RLM). The recoveryin step 704 includes either a beam failure recovery (BFR) or a radiolink failure (RLF) recovery. Detection of a beam failure in step 702 mayinclude a beam failure detection (BFD) at either beam group (e.g. TRP)or cell-level, or performance of a radio link monitor (RLM) atcell-level. In particular, the BFD procedure includes monitoring BFDreference signals (RSs), which may be a beam group BFD RS or a cell BFDRS. In step 704, the appropriate recovery procedure is performed (e.g.BFR at the beam group, BFR on the cell, or RLF on the cell). In step702, a beam group BFR can be independently performed on each beam group(e.g. TPR) in the cell in accordance with the beam failure configurationas illustrated in FIG. 6 .

FIG. 8 illustrates an example determination of the beam failureconfiguration according to some embodiments. As is illustrated, the beamfailure configuration 818 is determined from a set of beam failureparameters 802 that include beam failure parameters of a beam group 804and beam failure parameters of a cell 806. As is illustrated, the beamfailure parameters of the beam group 804 includes beam group BFD 808 andbeam group BFR 810. Similarly, beam failure parameters of the cell 806in this example includes cell BFD 812 and cell BFR 814. The set of beamfailure parameters 820 is processed in accordance with configurationprocess block 816 controls the beam failure configuration for beamfailure configuration 818 in accordance with configuration options andconfiguration rules as discussed below.

The beam failure configuration on the same cell from the set of beamfailure parameters 802 illustrated in FIG. 8 as determined in step 816falls within one of four options depending on whether beam group BFD 808and cell BFD can or cannot be simultaneously configured on the sameservicing cell and whether beam group BFD 812 and cell group 814 can besimultaneously configured. These options are graphically illustrated inFIGS. 9A through 9D.

In a first option 902 illustrated in FIG. 9A, beam group BFD 808 andcell BFD 812 cannot be simultaneously configured and beam group BFR 810and cell BFR 814 also cannot be simultaneously configured. In the firstoption, either beam group BFD 808 and beam group BFR 810 are configuredor cell BFD and cell BFR can be configured. In addition, a configurationcannot include simultaneous configuration of the beam group BFD 808/beamgroup BFR 810 and cell BFD 812/cell BFR 814.

In a second option 904 illustrated in FIG. 9B, beam group BFD 808 andcell BFD 812 can be simultaneously configured while beam group BFR 810and cell BFR 814 cannot be simultaneously configured. Although thisoption is less likely to occur than other options, if beam group BFD 808and cell BFD 812 will both trigger the configured BFR (either beam groupBFR 810 or cell BFR 814).

In a third option 906 illustrated in FIG. 9C, beam group BFD 808 cannotbe simultaneously configured with cell BFD 812 while beam group BFR 810can be simultaneously configured with cell BFR 814. In this option, forexample, the serving cell may only be configured with beam group BFD808, which will then trigger either of beam group BFR 810 or cell BFR814.

In a fourth option 908 illustrated in FIG. 9D, beam group BFD 808 can besimultaneously configured with cell BFD 812 while beam group BFR 810 canbe simultaneously configured with cell BFR 814. In this option, forexample, beam group BFD 808 can trigger beam group BFR 814 and cell BFD812 can trigger cell BFR 814.

Configuration 816 illustrated in FIG. 8 configures the beam failureconfiguration according to one of the options illustrated in FIGS. 9Athrough 9D. In step 818, configuration of a set of rules applicable tothe various configuration options are applied to the beam failureconfiguration. The result of steps 816 and 818 results in the beamfailure configuration illustrated in step 820. These considerations thatresult in the beam failure configuration controls how performance ofdetection of the beam failure in step 604, and subsequent recoveries,operates. Consequently, step 604 in accordance with the beam failureconfigurations as discussed below executes instructions to affect theserules.

FIG. 10 illustrates an example of step 818, where the beam failureconfiguration reflects rules that may be dependent on the configurationoptions that result from step 816. As illustrated in FIG. 10 , in step1002 a first rule that determines triggering of a beam group BFR or acell BFR based on threshold numbers of detected beam failures. The rulereflected in step 1002 is applicable to third option 906 and fourthoption 908, where beam group BFR 810 and cell BFR 814 can besimultaneously configured. In step 1002, the beam failure configurationcan be arranged such that beam group BFD 808 may forbid or may triggercell based BFR 814 in accordance with threshold values of the number ofdetected and number of working beams. Consequently, in step 1002triggering of the beam group BFR 814 or the cell BFD 812 is dependent onthe number of beam group failures are detected and the number of workingbeam groups. In particular, if one beam group fails based on beam groupBFD 808 and at least a first number of other beam groups are working(i.e. there are not ongoing BFRs), then beam group BFR will be triggeredfor the one failed beam group. However, if at least a second number ofgroup beams have failed as detected by the beam group BFD 808, then thebeam group configuration is arranged to either allow triggering of cellBFR 814 in response to beam group BFD 808 (based on triggeringconditions in step 604) or to immediately trigger the cell BFR 814 inresponse to beam group BFD 808. Additionally, if at least a third numberof beam groups are working, or have become working through successfulbeam recovery, then triggering of cell BFRs is not allowed and anyongoing cell BFRs should be stopped.

In the first rule implementation reflected in step 1002, the thresholdnumbers (first number, second number, third number) may be fixed in aspecification or may be signaled by a base station. In one particularexample, the first number may be 1, the second number may be the numberof beam groups in the cell, and the third number may be 1. However,particular combinations of parameters can be application specific.

In step 1004, configuration consistent with a second rule isimplemented. The second rule is applicable to third and fourth options(options 906 and 908) where both beam group BFR 810 and cell BFR 814 canbe simultaneously configured. In step 1004, under this rule, the beamfailure configuration may be arranged such that triggering a cell BFR814 may forbid triggering a beam group BFR 810. Further, if a cell BFR814 is ongoing, then any ongoing beam group BFRs 810 may be terminatedand new beam group BFRs 810 will not be triggered.

In step 1006 a third rule is implanted that is applicable when both beamgroup BFD 808 and cell BFD 812 may be configured (e.g. option 4 908). Inaccordance with rule 3 in step 1006, the beam failure configuration maybe arranged such that BFD reference signals (RSs) for both beam groupBFD 808 and cell BFD 812 can be configured independently or dependently.As discussed above, during a BFD the indicated BFD RSs are monitor. Insome beam failure configurations the BFD RSs for a group beam BFD 808may be independently configured from the BFD RSs for a cell BFR 814.Alternatively, in some beam failure configurations, the BFD RSs forgroup beam BFDs 808 may be identical, a subset of, or include all of theset of BFD RSs for cell BFRs 814. For example, if beam group specificBFD RSs includes an RS1 and RS2 for beam group 1 and beam group 2, thenboth RS1 and RS2 are configured to cell BFD RSs as well.

As discussed above, embodiments of the present disclosure can also beapplicable to configurations between beam group BFD/BFR and cellRLM/RLF. Similar options as those indicated above can be applied duringthe configuration with cell RLM replacing cell BFD 812 in the discussionand cell RLF replacing cell BFR 814 in the discussion. However, thefollowing additional rules may be applicable with regard to cell (e.g.SpCell) RLFs. FIG. 11 illustrates an embodiment of step 818 where thebeam failure configuration reflects the appropriate RLF rules.

In step 1102 of FIG. 11 , a first RLF rule is configured. The first ruleis applicable where a beam group BFR 810 and a cell RLF can besimultaneously configured (like options 3 and 4 above). In step 1102,the beam failure configuration may be arranged such that a beam groupBFD 808 may either forbid or may trigger a cell RLF based on thresholdnumbers of detected beam failures detected by beam group BFDs 808. Inparticular, if one beam group fails as detected by its beam group BFD808 and at least a first number of other beam groups are working (e.g.,there are no ongoing beam recoveries), then a beam group BFR 810 will betriggered for this one failed beam group. If at least a second number ofbeam groups have failed, then beam failure configuration states thateither the cell RLF is allowed to be triggered based on existingtriggering conditions or the cell RLF is immediately triggered inresponse to the beam group BFD 808. If at least a third number of beamgroups are working, or become working through successful beam recovery,then the cell RLF is not allowed to be triggered and ongoing cell RLFshould be stopped (e.g., the RLF timer should not be started and shouldbe stopped if it is already started for ongoing cell RLFs). Thethreshold values (first number, second number, and third number) can bereceived from a base station.

In step 1104, a second RLF rule is implemented. In the second rule, thebeam failure configuration can be arranged such that operation of a cellRLF forbids operation of a beam group BFR. If a cell RLF has beentriggered, for example on an SpCell, and a corresponding connectionreestablishment procedure is ongoing, then beam group BFRs should beterminated and further beam group BFRs should not be triggered.

In step 1106, a third RLF rule is implemented. In the third rule, thebeam failure configuration can be arranged such that configuration ofbeam group BFD RSs and cell RLM RSs can be dependent. Consequently, allbeam specific BFD RSs can be identical, be a subset of, or include allof the cell RLM RSs. Consequently, if the beam group BFD RSs include RS1and RS2 for beam group 1 and beam group 2, respectively, then both RS1and RS2 can be used as cell RLM RSs.

In step 1108 a fourth RLF rule is implemented. In the fourth rule, thebeam failure configuration can be arranged such that if the cell RLF hasbeen triggered (i.e. an RLF timer has been started), the RLF time can beadjusted (reduced or speeded up) for a determined amount of time or acertain fraction of the total expiration duration of the RLF timer upondetection of beam group failures determined by a beam group BFD 808.

In a first embodiment of the fourth RLF rule of step 1108, the RLF timermay be adjusted in response to a number of consecutive beam group BFDindicators from the beam group BFD 808 from the same beam group. Inanother example, the RLF timer may be adjusted when a number ofconsecutive beam group BFD indicators across all beam groups asindicated by the beam group BFD 808 is received. For example, a certainnumber of consecutive BFD indicators can be received from a first TRPand another number from a second TRP resulting in the number of beamgroup BFD indicators.

In a second embodiment of the fourth RLF rule of step 1108, the RLFtimer may be adjusted by a certain amount in accordance with each beamgroup BFD indicator determined by the beam group BFD 808.

FIG. 12 illustrates operation 1200 of a base station (BS) according tosome embodiments of the present invention. In step 1202, the BSconfigured the UE with parameters applicable to determining the beamfailure configuration as discussed above. For example, particularthreshold values as discussed above may be downloaded to UE during oneor more DCI communications with the UE. In step 1204, the BS 1204performs recovery functions in response to BFRs or RLFs from the UE thatresult from the beam failure configurations discussed here.

RECITATION OF VARIOUS ASPECTS OF THE PRESENT DISCLOSURE

Aspect 1: A method of wireless communication performed by a userequipment (UE), the method comprising: receiving, from a base station(BS), a communication indicating a beam failure configuration for aserving cell, the beam failure configuration including at least one of abeam failure parameter of a beam group or a beam failure parameter of acell; and detecting, in the serving cell based at least in part on thebeam failure configuration, a beam failure.

Aspect 2: The method of aspect 1, wherein: the beam failureconfiguration for the serving cell includes the beam failure parameterof the beam group and does not include the beam failure parameter of thecell; and the detecting the beam failure comprises detecting the beamfailure based on the beam failure parameter of the beam group.

Aspect 3: The method of aspect 1 or 2, wherein the beam failureparameter of the beam group comprises at least one of atransmission-reception point (TRP)-specific beam failure detection (BFD)parameter or a TRP-specific beam failure recovery (BFR) parameter.

Aspect 4: The method of any of aspects 1-3, wherein: the beam failureconfiguration for the serving cell includes a plurality oftransmission-reception point (TRP)-specific beam failure parametersassociated with a plurality of TRPs; and the detecting the beam failurecomprises independently monitoring for beam for each of the plurality ofTRPs.

Aspect 5: The method of aspect 1, wherein: the beam failureconfiguration for the serving cell includes the beam failure parameterof the cell and does not include the beam failure parameter of the beamgroup.

Aspect 6: The method of aspect 5, wherein the beam failure parameter ofthe cell comprises at least one of a cell-level beam failure detection(BFD) parameter or a cell-level beam failure recovery (BFR) parameter.

Aspect 7: The method of aspect 1, wherein: the beam failureconfiguration for the serving cell includes the beam failure parameterof the beam group and the beam failure parameter of the cell, whereinthe beam failure parameter of the beam group includes a beamgroup-specific beam failure detection (BFD) parameter and the beamfailure parameter of the cell includes a cell-level BFD parameter.

Aspect 8: The method of aspect 7, wherein the detecting the beam failurecomprises: performing a first beam failure detection (BFD) based on thebeam group-specific beam failure detection parameter; and performing asecond BFD based on the cell-level BFD parameter.

Aspect 9: The method of aspect 7 or 8, wherein: the beam failureconfiguration for the serving cell includes a beam group-specific beamfailure recovery (BFR) parameter and does not include a cell-level beamfailure recovery (BFR) parameter, the method further comprisingperforming a BFR, in response to the detecting the beam failure, basedon the beam group-specific BFR parameter.

Aspect 10: The method of aspect 7 or 8, wherein: the beam failureconfiguration for the serving cell includes a cell-level beam failurerecovery (BFR) parameter and does not include a beam group-specific beamfailure recovery (BFR) parameter, the method further comprisingperforming, in response to the detecting the beam failure, a BFR basedon the cell-level BFR parameter.

Aspect 11: The method of any of aspects 8-10, wherein: the performingthe first BFD based on the beam group-specific beam failure detectionparameter comprises monitoring for at least one transmission-receptionpoint (TRP)-specific BFD reference signal (RS); and the performing thesecond BFD based on the cell-level BFD parameter comprises monitoringfor at least one cell-level BFD RS.

Aspect 12: The method of any of aspects 8-11, wherein the at least oneTRP-specific BFD reference signal (RS) is independent of the at leastone cell-level BFD RS.

Aspect 13: The method of any of aspects 8-11, wherein the at least oneTRP-specific BFD reference signal (RS) is based on the at least onecell-level BFD RS.

Aspect 14: The method of aspect 1 or 7, wherein: the beam failureparameter of the beam group includes a transmission-reception point(TRP)-specific beam failure detection (BFD) parameter and a TRP-specificbeam failure recovery (BFR) parameter; and the detecting the beamfailure comprises performing a BFD based on the TRP-specific BFDparameter, the method further comprising: performing, in response to theBFD indicating the beam failure, a BFR based on the TRP-specific BFRparameter.

Aspect 15: The method of aspect 1 or 7, wherein: the beam group-specificbeam failure detection parameter includes a transmission-reception point(TRP)-specific beam failure detection (BFD) parameter; the cell-levelbeam failure detection parameter includes a cell-level beam failurerecovery (BFR) parameter; and the detecting the beam failure comprisesperforming a BFD based on the TRP-specific BFD parameter, the methodfurther comprising: performing, in response to the BFD indicating a beamfailure, a BFR based on the cell-level BFR parameter.

Aspect 16: The method of aspect 1 or 7, wherein: the beam group-specificbeam failure detection parameter includes a transmission-reception point(TRP)-specific beam failure detection (BFD) parameter and a TRP-specificbeam failure recovery (BFR) parameter; the cell-level beam failuredetection parameter includes a cell-level BFD parameter and a cell-levelBFR parameter; and the detecting the beam failure comprises: performinga first BFD based on the TRP-specific BFD parameter; and performing asecond BFD based on the cell-level BFD parameter.

Aspect 17: The method of aspect 16, further comprising at least one of:performing, in response to the first BFD indicating a beam failure, afirst BFR based on the TRP-specific BFR parameter; or performing, inresponse to the second BFD indicating a beam failure, a second BFR basedon the cell-level BFR parameter.

Aspect 18: The method of any of aspects 1-17, wherein: the beam failureconfiguration for the serving cell includes a plurality oftransmission-reception point (TRP)-specific beam failure parametersassociated with a plurality of TRPs; and the detecting the beam failurecomprises: performing a beam failure detection (BFD) for each of theplurality of TRPs; and performing, based on a number of the BFDsindicating a beam failure, a beam failure recovery (BFR).

Aspect 19: The method of aspect 18, wherein the performing the BFRcomprises: performing, in response to the number being less than athreshold, a TRP-specific BFR.

Aspect 20: The method of aspect 18, wherein the performing the BFRcomprises: performing, in response to the number being greater than athreshold, a cell-level BFR.

Aspect 21: The method of aspect 20, further comprising: immediatelytriggering the performing of the cell-level BFR in response to thenumber being greater than the threshold.

Aspect 22: The method of any of aspects 18-21, wherein the performingthe BFR comprises: disallowing a cell-level BFR when a threshold numberof working TRPs is exceeded.

Aspect 23: The method of any of aspects 18-22, further comprising:receiving, from the base station of the serving cell, an indication ofat least one threshold value for determining whether to perform aTRP-specific BFR or a cell-level BFR.

Aspect 24: The method of any of aspects 1-23, wherein further comprises:performing, in response to detection of the beam failure, a cell-levelbeam failure recovery (BFR); and terminating any active TRP-specificBFRs.

Aspect 25: The method of aspect 24, further comprising: refraining frominitiating any TRP-specific BFRs while performing the cell-level BFR.

Aspect 26: The method of aspect 1 or 7, wherein: the beam group-specificbeam failure detection parameter includes a plurality oftransmission-reception point (TRP)-specific beam failure parametersassociated with a plurality of TRPs; and the cell-level beam failuredetection parameter includes a radio-link failure (RLF) parameter; thedetecting the beam failure comprises performing a beam failure detection(BFD) for each of the plurality of TRPs, the method further comprisingperforming, based on a number of the BFDs indicating a beam failure, arecovery.

Aspect 27: The method of aspect 26, wherein the performing the recoverycomprises: performing, in response to the number being (a) less than athreshold, a TRP-specific BFR; or (b) greater than a threshold, an RLFrecovery.

Aspect 28: The method of aspect 26, wherein the performing the recoverycomprises: performing, in response to the number being greater than athreshold, an RLF recovery.

Aspect 29: The method of aspect 26 or 28, wherein the performing therecovery comprises: immediately performing the RLF recovery in responseto the number being greater than the threshold.

Aspect 30: The method of any of aspects 26-29, wherein performing therecovery comprises: disallowing an RLF recovery when a threshold numberof working TRPs is exceeded.

Aspect 31: The method of any of aspects 26-30, further comprising:receiving, from the base station of the serving cell, an indication ofat least one threshold value for determining whether to perform aTRP-specific beam failure recover (BFR) or an RLF recovery.

Aspect 32: The method of any of aspects 26-31, wherein the performingthe recovery includes: performing an RLF recovery; and terminating anyactive TRP-specific beam failure recovery (BFR).

Aspect 33: The method of any of aspects 26-32, further comprising:refraining from initiating any TRP-specific BFRs while performing theRLF recovery.

Aspect 34: The method of aspect 1 or 7, wherein detecting the beamfailure comprises: performing a beam failure detection (BFD) based onthe beam group specific beam failure detection parameter; and performinga radio link monitoring (RLM) based on the cell-level beam failuredetection parameter.

Aspect 35: The method of aspect 34, wherein: the performing the BFDbased on the beam group-specific beam failure detection parametercomprises monitoring for at least one transmission-reception point(TRP)-specific BFD reference signal (RS); and the performing the RLMbased on the cell-level beam failure detection parameter comprisesmonitoring for at least one RLM RS.

Aspect 36: The method of aspect 35, wherein the at least oneTRP-specific BFD RS is based on the at least one RLM RS.

Aspect 37: The method of aspect 1 or 7, further comprising: triggering aradio link failure (RLF) recovery, the method further comprising:performing, following the triggering of the RLF recovery, a plurality oftransmission-reception point (TRP)-specific BFDs; and adjusting, basedon a consecutive number of the TRP-specific BFDs indicating a beamfailure exceeding a threshold, a timer associated with the RLF recovery.

Aspect 38: The method of aspect 37, wherein the adjusting the timerincludes increasing or decreasing the timer by at least one of apredetermined amount of time or a percentage of a duration of the timer.

Aspect 39: The method of aspect 37 or 38, wherein the consecutive numberof the TRP-specific BFD indicating the beam failure is based on a singleTRP.

Aspect 40: The method of aspect 37 or 38, wherein the consecutive numberof the TRP-specific BFDs indicating the beam failure is based on aplurality of TRPs.

Aspect 41: The method of any of aspects 37-40, wherein the adjusting thetimer includes adjusting the timer based on a number of TRPs associatedwith the TRP-specific BFDs indicating the beam failure.

Information and signals may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the above description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a DSP, an ASIC, an FPGA or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general-purpose processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described above can be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations. Also, as used herein, including in the claims, “or” as usedin a list of items (for example, a list of items prefaced by a phrasesuch as “at least one of” or “one or more of”) indicates an inclusivelist such that, for example, a list of [at least one of A, B, or C]means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

As those of some skill in this art will by now appreciate and dependingon the particular application at hand, many modifications, substitutionsand variations can be made in and to the materials, apparatus,configurations and methods of use of the devices of the presentdisclosure without departing from the spirit and scope thereof. In lightof this, the scope of the present disclosure should not be limited tothat of the particular embodiments illustrated and described herein, asthey are merely by way of some examples thereof, but rather, should befully commensurate with that of the claims appended hereafter and theirfunctional equivalents.

What is claimed is:
 1. A method of wireless communication performed by auser equipment (UE), the method comprising: receiving, from a basestation (BS), a communication indicating a beam failure configuration,the beam failure configuration including at least one of a beam failureparameter of a beam group or a beam failure parameter of a cell, whereinthe at least one of the beam failure parameter of the beam group or thebeam failure parameter of the cell is associated with a cell-leveltriggering condition or a beam group-specific triggering condition forinitiating a beam failure recovery (BFR) procedure; and detecting, in aserving cell based at least in part on the beam failure configuration, abeam failure.
 2. The method of claim 1, wherein: the beam failureconfiguration includes the beam failure parameter of the beam group anddoes not include the beam failure parameter of the cell; and thedetecting the beam failure comprises detecting the beam failure based onthe beam failure parameter of the beam group.
 3. The method of claim 2,wherein the beam failure parameter of the beam group comprises at leastone of a transmission-reception point (TRP)-specific beam failuredetection (BFD) parameter or a TRP-specific BFR parameter.
 4. The methodof claim 2, wherein: the beam failure configuration includes a pluralityof TRP-specific beam failure parameters associated with a plurality ofTRPs; and the detecting the beam failure comprises independentlymonitoring for beam for each of the plurality of TRPs.
 5. The method ofclaim 1, wherein: the beam failure configuration includes the beamfailure parameter of the cell and does not include the beam failureparameter of the beam group.
 6. The method of claim 5, wherein the beamfailure parameter of the cell comprises at least one of a cell-level BFDparameter or a cell-level BFR parameter.
 7. The method of claim 1,wherein: the beam failure configuration includes the beam failureparameter of the beam group and the beam failure parameter of the cell;and the beam failure parameter of the beam group includes a beamgroup-specific BFD parameter and the beam failure parameter of the cellincludes a cell-level BFD parameter.
 8. The method of claim 7, whereinthe detecting the beam failure comprises: performing a first BFD basedon the beam group-specific BFD parameter; and performing a second BFDbased on the cell-level BFD parameter.
 9. The method of claim 8, whereinthe beam failure configuration includes a beam group-specific BFRparameter and does not include a cell-level BFR parameter, the methodfurther comprising: performing a BFR, in response to performing thefirst BFD, based on the beam group-specific BFR parameter.
 10. Themethod of claim 8, wherein the beam failure configuration includes acell-level BFR parameter and does not include a beam group-specific BFRparameter, the method further comprising: performing, in response to theperforming the second BFD, a BFR based on the cell-level BFR parameter.11. The method of claim 8, wherein: the performing the first BFD basedon the beam group-specific beam failure detection parameter comprisesmonitoring for at least one TRP-specific BFD reference signal (RS); andthe performing the second BFD based on the cell-level BFD parametercomprises monitoring for at least one cell-level BFD RS.
 12. The methodof claim 7, wherein: the beam failure parameter of the beam groupincludes a TRP-specific BFD parameter and a TRP-specific BFR parameter;and the detecting the beam failure comprises performing a BFD based onthe TRP-specific BFD parameter, the method further comprising:performing, in response to the BFD indicating the beam failure, a BFRbased on the TRP-specific BFR parameter.
 13. The method of claim 7,wherein: the beam group-specific BFD parameter includes a TRP-specificBFD parameter; the cell-level BFD parameter includes a cell-level BFRparameter; and the detecting the beam failure comprises performing a BFDbased on the TRP-specific BFD parameter, the method further comprising:performing, in response to the BFD indicating a beam failure, a BFRbased on the cell-level BFR parameter.
 14. The method of claim 7,wherein: the beam group-specific BFD parameter includes a TRP-specificBFD parameter and a TRP-specific BFR parameter; the cell-level BFDparameter includes a cell-level BFD parameter and a cell-level BFRparameter; and the detecting the beam failure comprises: performing afirst BFD based on the TRP-specific BFD parameter; and performing asecond BFD based on the cell-level BFD parameter.
 15. The method ofclaim 14, further comprising at least one of: performing, in response tothe first BFD indicating the beam failure, a first BFR based on theTRP-specific BFR parameter; or performing, in response to the second BFDindicating the beam failure, a second BFR based on the cell-level BFRparameter.
 16. The method of claim 1, wherein: the beam failureconfiguration includes a plurality of TRP-specific beam failureparameters associated with a plurality of TRPs; and the detecting thebeam failure comprises: performing a BFD for each of the plurality ofTRPs; and performing, based on a number of BFDs indicating the beamfailure, a BFR.
 17. The method of claim 16, wherein the performing theBFR comprises: performing, in response to the number being less than afirst threshold, a TRP-specific BFR; performing, in response to thenumber being greater than a second threshold, a cell-level BFR; ordisallowing the cell-level BFR when a threshold number of working TRPsis exceeded.
 18. The method of claim 16, further comprising: receiving,from the base station of the serving cell, an indication of at least onethreshold value for determining whether to perform a TRP-specific BFR ora cell-level BFR.
 19. The method of claim 18, wherein further comprises:performing, in response to detection of the beam failure, a cell-levelBFR; and terminating any active TRP-specific BFRs.
 20. The method ofclaim 7, wherein: the beam group-specific BFD parameter includes aplurality of TRP-specific beam failure parameters associated with aplurality of TRPs; and the detecting the beam failure comprisesperforming a BFD for each of the plurality of TRPs, the method furthercomprising: performing, based on a number of BFDs indicating the beamfailure, a recovery.
 21. The method of claim 20, wherein: the cell-levelBFD parameter includes a radio-link failure (RLF) parameter; and theperforming the recovery comprises: performing, in response to the numberbeing less than a first threshold, a TRP-specific BFR; performing, inresponse to the number being greater than a second threshold, an RLFrecovery based on the RLF parameter; or disallowing an RLF recovery whena threshold number of working TRPs is exceeded.
 22. The method of claim20, further comprising: receiving, from the base station, an indicationof at least one threshold value for determining whether to perform aTRP-specific BFR or an RLF recovery.
 23. The method of claim 20, whereinthe performing the recovery includes: performing an RLF recovery; andterminating any active TRP-specific BFR.
 24. The method of claim 7,wherein detecting the beam failure comprises: performing a BFD based onthe beam group-specific BFD parameter; and performing a RLM based on thecell-level BFD parameter.
 25. The method of claim 24, wherein: theperforming the BFD based on the beam group-specific beam failuredetection parameter comprises monitoring for at least onetransmission-reception point (TRP)-specific BFD reference signal (RS);and the performing the RLM based on the cell-level beam failuredetection parameter comprises monitoring for at least one RLM RS. 26.The method of claim 7, further comprising: triggering a radio linkfailure (RLF) recovery; performing, following the triggering of the RLFrecovery, a plurality of transmission-reception point (TRP)-specificBFDs; and adjusting, based on a consecutive number of the TRP-specificBFDs indicating the beam failure exceeding a threshold, a timerassociated with the RLF recovery.
 27. The method of claim 26, wherein:the adjusting the timer includes increasing or decreasing the timer byat least one of a predetermined amount of time or a percentage of aduration of the timer; or the adjusting the timer includes adjusting thetimer based on a number of TRPs associated with the TRP-specific BFDsindicating the beam failure.
 28. A user equipment (UE), comprising: amemory; a processor coupled to the memory; and a transceiver coupled tothe processor and configured to: receive, from a base station (BS), acommunication indicating a beam failure configuration, the beam failureconfiguration including at least one of a beam failure parameter of abeam group or a beam failure parameter of a cell, wherein the at leastone of the beam failure parameter of the beam group or the beam failureparameter of the cell is associated with a cell-level triggeringcondition or a beam group-specific triggering condition for initiating abeam failure recovery (BFR) procedure, wherein the processor isconfigured to: detect, in a serving cell based at least in part on thebeam failure configuration, a beam failure.
 29. A non-transitorycomputer-readable medium having program code recorded thereon foroperation on a user equipment (UE), the program code comprising: codefor causing a UE to receive, from a base station (BS), a communicationindicating a beam failure configuration, the beam failure configurationincluding at least one of a beam failure parameter of a beam group or abeam failure parameter of a cell, wherein the at least one of the beamfailure parameter of the beam group or the beam failure parameter of thecell is associated with a cell-level triggering condition or a beamgroup-specific triggering condition for initiating a beam failurerecovery (BFR) procedure; and code for causing the UE to detect, in aserving cell based at least in part on the beam failure configuration, abeam failure.
 30. A user equipment (UE), comprising: means forreceiving, from a base station (BS), a communication indicating a beamfailure configuration, the beam failure configuration including at leastone of a beam failure parameter of a beam group or a beam failureparameter of a cell, wherein the at least one of the beam failureparameter of the beam group or the beam failure parameter of the cell isassociated with a cell-level triggering condition or a beamgroup-specific triggering condition for initiating a beam failurerecovery (BFR) procedure; and means for detecting, in a serving cellbased at least in part on the beam failure configuration, a beamfailure.